Bioengineering

15 pages, 1491 KB

Open AccessEditor’s ChoiceArticle

Focal Hepatic Hypoperfusion After Normothermic Machine Perfusion of Liver Grafts Is Associated with a Higher Comprehensive Complication Index

by Felicia Kneifel, Felix Becker, Qing Wen Lin, Carsten Szardenings, Sebastian Kubasch, Arne Riegel, Haluk Morgül, Isabelle Flammang, Shadi Katou, Andreas Pascher and Philipp Houben

Bioengineering 2026, 13(7), 729; https://doi.org/10.3390/bioengineering13070729 - 24 Jun 2026

Viewed by 425

Abstract

Background: Normothermic machine perfusion (NMP) is increasingly being used to improve organ utilization in liver transplantation (LT). However, its non-physiological perfusion setting may cause focal hepatic hypoperfusion (FHH), which remains insufficiently characterized in terms of its incidence, risk factors, and clinical impact. Methods: [...] Read more.

Background: Normothermic machine perfusion (NMP) is increasingly being used to improve organ utilization in liver transplantation (LT). However, its non-physiological perfusion setting may cause focal hepatic hypoperfusion (FHH), which remains insufficiently characterized in terms of its incidence, risk factors, and clinical impact. Methods: Data on liver grafts that underwent NMP prior to LT at the Department of General, Visceral, and Transplant Surgery, University Hospital Münster, between October 2019 and August 2024 were retrospectively analyzed. Recipients who underwent contrast-enhanced computed tomography within 30 days post-LT were included. The primary outcomes were the Comprehensive Complication Index (CCI) and overall graft survival rate. Ninety-one patients met the inclusion criteria and were stratified according to the presence of FHH in the FHH+ (n = 27) and FHH- (n = 64) groups. Results: FHH was detected in 29.7% of the grafts. Higher graft weight was the only independent predictor of FHH. In addition, graft weight correlated with the extent of FHH (τ = 0.40, p < 0.001). FHH did not affect graft or patient survival but was associated with higher CCI scores (p = 0.001) and prolonged intensive care unit length of stay (p = 0.028). Conclusions: FHH is a common radiological finding after NMP. Although it does not affect graft loss, its association with a higher complication burden warrants further attention. Whether avoiding NMP in very heavy grafts could reduce the incidence of FHH remains to be determined. Full article

(This article belongs to the Special Issue Bioengineering Liver Transplantation—3rd Edition)

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16 pages, 2017 KB

Open AccessEditor’s ChoiceArticle

From Waste to Value: Urine and Ash as Sustainable Sources for Green Ammonia and Calcium Phosphate Fertilizers

by Zhengyu Li, Eduard Tiganescu, Kevin Böhm, Muhammad Jawad Nasim and Claus Jacob

Bioengineering 2026, 13(7), 720; https://doi.org/10.3390/bioengineering13070720 - 24 Jun 2026

Viewed by 760

Abstract

Turning waste materials into renewed value is a central aspect of any future circular (bio)economy. Urine and ash are two prominent waste materials produced globally and in considerable amounts each year. Both contain several interesting substances that are so far de facto lost [...] Read more.

Turning waste materials into renewed value is a central aspect of any future circular (bio)economy. Urine and ash are two prominent waste materials produced globally and in considerable amounts each year. Both contain several interesting substances that are so far de facto lost or may even pose a threat to the environment. Urine from industrial-scale farming, for instance, is responsible for significant pollution of soil and groundwater with nitrogen and phosphorous, yet N and P are also high-demand substances in agriculture and industry. Similarly, ash is rich in several interesting metal ions, but is still usually disposed of in a landfill. Using a sequence of simple yet effective biological and chemical processes, it may be possible to convert these two unwanted materials into “green” ammonia and calcium phosphate, both valuable high-demand substances with numerous applications, and with few potentially valuable leftovers still to be dealt with. Eventually, and after considering some of the logistics of the process, such as the collection of materials, this “urinash process” may be upscaled to effectively reduce waste by turning it into renewed value, thus also substituting for—some of—both the energy-intensive synthesis of grey ammonia and the destructive mining for phosphate salts. Full article

(This article belongs to the Special Issue Anaerobic Digestion Advances in Biomass and Waste Treatment)

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11 pages, 995 KB

Open AccessEditor’s ChoiceArticle

Biodegradable Temporizing Matrix for Facial Reconstruction Following Mohs Micrographic Surgery: A Multi-Subunit Analysis

by Alexandra L. Martinez and James F. Thornton

Bioengineering 2026, 13(7), 732; https://doi.org/10.3390/bioengineering13070732 - 24 Jun 2026

Viewed by 599

Abstract

Background: Biodegradable Temporizing Matrix (BTM) is a synthetic, biodegradable polyurethane dermal substitute that promotes neodermis formation and supports re-epithelialization by secondary intention. However, published experience with BTM in facial reconstruction is limited to small case series with narrow anatomic indications, and its performance [...] Read more.

Background: Biodegradable Temporizing Matrix (BTM) is a synthetic, biodegradable polyurethane dermal substitute that promotes neodermis formation and supports re-epithelialization by secondary intention. However, published experience with BTM in facial reconstruction is limited to small case series with narrow anatomic indications, and its performance across multiple distinct facial subunits has not been systematically characterized. Methods: A retrospective case series was conducted of all patients who underwent nasal, periocular, or scalp reconstruction with BTM following Mohs micrographic surgery (MMS) at a single tertiary academic center. Patient demographics, defect characteristics, healing times, complications, and secondary procedures were recorded. Results: A total of 135 patients were included: 67 nasal, 40 periocular, and 28 scalp. Overall complication rates were 7.5%, 20.0%, and 17.9%, respectively. The majority of patients across all sites achieved definitive coverage by secondary intention without skin grafting. Lower eyelid involvement was the strongest independent predictor of ocular complications in the periocular cohort, and prior radiation was the dominant predictor of scalp complications. Conclusions: In this retrospective series, BTM demonstrated favorable outcomes for facial reconstruction following MMS across nasal, periocular, and scalp subunits, reliably supporting secondary re-epithelialization and functioning as definitive reconstruction, a temporizing agent, and a lining adjunct for staged forehead flap reconstruction. Prospective comparative studies are needed to confirm these findings. Full article

(This article belongs to the Special Issue Biomedical Engineering for Facial Reconstruction)

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18 pages, 2092 KB

Open AccessEditor’s ChoiceArticle

The Impact of a Heated Effleurage and Heated Tapotement Massage on Low-Back Discomfort from a Seat

by Matt M. Mallette, Nathaniel Gur-Arie, Malak Almonjed and Nicola Gerrett

Bioengineering 2026, 13(6), 708; https://doi.org/10.3390/bioengineering13060708 - 20 Jun 2026

Viewed by 681

Abstract

Lower back pain (LBP) is highly prevalent, and while non-pharmacological treatments exist such as heat or massage, they are rarely combined in a convenient manner. We examined the impact of two different heated massage protocols delivered from an automotive seat on LBP within [...] Read more.

Lower back pain (LBP) is highly prevalent, and while non-pharmacological treatments exist such as heat or massage, they are rarely combined in a convenient manner. We examined the impact of two different heated massage protocols delivered from an automotive seat on LBP within typical commute times. Seventeen adults (eight females) with chronic, non-specific LBP (~6/10 initial back pain) evaluated a heated effleurage or heated tapotement massage—in a randomized order—applied to the lower back, upper thighs, and gluteal region while seated. Each visit included a 20 min control followed by a 20 min heated massage (30 min rest between), with thermal and subjective measurements assessed throughout. Before and after each 20 min session, viscoelastic properties of participants’ lower back muscles were assessed with a myotonometer. Heated massage increased skin temperature, thermal sensation and comfort vs. control (p ≤ 0.039). Both heated massage conditions reduced LBP at 10- and 20 min and reduced subjective tightness at 20 min (p ≤ 0.023). Tapotement produced an earlier reduction in tightness at 10 min and had a greater reduction than effleurage at 20 min (p ≤ 0.026). Increased tissue elasticity was observed in the heated tapotement condition (p ≤ 0.031). Seat-based heated massage offers a convenient method to alleviate LBP, potentially from changes to posterior chain tissue properties. Full article

(This article belongs to the Special Issue Applied Biomechanics in Rehabilitation and Ergonomics)

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36 pages, 4092 KB

Open AccessEditor’s ChoiceArticle

Functional Profiling in Paralympic Water Polo Using Deep Learning, Stereo Vision, and Phase-Based Kinematic Analysis: A Pilot Study

by Andrea Zanela

Bioengineering 2026, 13(6), 707; https://doi.org/10.3390/bioengineering13060707 - 19 Jun 2026

Viewed by 591

Abstract

Paralympic water polo requires classification systems that reflect sport-specific functional performance under ecologically valid conditions. This pilot study proposes a task-specific kinematic profiling framework for deriving objective, biomechanically interpretable descriptors of residual motor function. Five male national-level water polo athletes—three with eligible motor [...] Read more.

Paralympic water polo requires classification systems that reflect sport-specific functional performance under ecologically valid conditions. This pilot study proposes a task-specific kinematic profiling framework for deriving objective, biomechanically interpretable descriptors of residual motor function. Five male national-level water polo athletes—three with eligible motor impairments and two able-bodied reference participants—performed standardized sport-specific tasks comprising upright floating, vertical propulsion, unilateral passing, non-contested shooting, and contested shooting under physical opposition. Stereoscopic video, OpenPose-based three-dimensional reconstruction, and phase-based analysis were used to extract features and composite indices of postural control, propulsion capacity, upper-limb residual function, and resistance to perturbation. Automatic ball-release detection matched manual frame-level verification in all 128 analyzed ball-related trials. Within the task-specific indices, where higher scores indicate greater functional burden, core values ranged from 0.05–0.15 for upright floating, 0.29–0.68 for combined arm-and-leg vertical propulsion, and 0.040–0.148 for contested shooting across the available subject–side combinations. The profiles showed task- and side-specific differences in stabilization, propulsion, and post-contact motor reorganization. The framework uses pose estimation as a quantitative measurement tool and treats visibility interruptions as functionally meaningful events rather than noise. It is not intended to replace official classification procedures, but to provide transparent and interpretable candidate descriptors for future evidence-based classification research in Paralympic water polo. Full article

(This article belongs to the Special Issue Dynamic Insights: Unveiling the Biomechanics of Sport Through Motion Analysis, 2nd Edition)

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17 pages, 4776 KB

Open AccessEditor’s ChoiceArticle

Effects of Sintering Parameters on the Microstructure and Optical Transmittance of Monolithic 4 mol% Yttria-Partially Stabilized Zirconia

by Taek-Jun Chung, Myung-Joo Kim, Ho-Beom Kwon, Bongju Kim and Young-Jun Lim

Bioengineering 2026, 13(6), 702; https://doi.org/10.3390/bioengineering13060702 - 19 Jun 2026

Viewed by 582

Abstract

High-translucency 4 mol% yttria-partially stabilized zirconia (4Y-PSZ) is widely used for esthetic restorations, but sintering conditions that balance translucency and microstructural control remain unclear. This study evaluated the independent effects of peak temperature, holding time, and heating rate on the microstructure and total [...] Read more.

High-translucency 4 mol% yttria-partially stabilized zirconia (4Y-PSZ) is widely used for esthetic restorations, but sintering conditions that balance translucency and microstructural control remain unclear. This study evaluated the independent effects of peak temperature, holding time, and heating rate on the microstructure and total luminous transmittance of monolithic 4Y-PSZ. Disks were sintered at peak temperatures of 1470–1560 °C, holding times of 30–180 min, and heating rates of 3–10 °C/min. Grain size and internal defect density (≥0.5 µm) were quantified by scanning electron microscopy, and total luminous transmittance at 0.5 mm thickness was measured using a spectrophotometer. Higher peak temperatures and longer holding times increased grain size (0.481 ± 0.020 to 0.785 ± 0.035 µm, and 0.503 ± 0.037 to 0.730 ± 0.041 µm, respectively) and reduced defect density, whereas heating rate had no significant effect on either. Transmittance remained within a narrow range (approximately 40–43% at 0.5 mm) across all schedules, with 1560 °C yielding the lowest value. These findings indicate that the microstructure of monolithic 4Y-PSZ is governed primarily by peak temperature and holding time, while transmittance is relatively insensitive to the sintering schedule. Practically, a peak temperature of 1500–1530 °C with a 1–2 h hold provides a robust processing window balancing densification, grain coarsening, and optical performance for clinical workflows. Full article

(This article belongs to the Special Issue Dental Implant Reconstruction and Biomechanical Evaluation, 3rd Edition)

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54 pages, 85092 KB

Open AccessEditor’s ChoiceReview

Advances and Prospects in MOF-Based Platforms for Tumor Hyperthermia

by Diyi Feng and Liqin Ge

Bioengineering 2026, 13(6), 693; https://doi.org/10.3390/bioengineering13060693 - 17 Jun 2026

Viewed by 730

Abstract

Metal-organic framework (MOF)-based materials have become promising platforms for tumor hyperthermia by integrating energy conversion, tumor microenvironment regulation, and multimodal therapy within programmable porous structures. This review summarizes recent advances in intrinsic MOFs, MOF composites, and MOF-derived materials for photothermal therapy, microwave hyperthermia, [...] Read more.

Metal-organic framework (MOF)-based materials have become promising platforms for tumor hyperthermia by integrating energy conversion, tumor microenvironment regulation, and multimodal therapy within programmable porous structures. This review summarizes recent advances in intrinsic MOFs, MOF composites, and MOF-derived materials for photothermal therapy, microwave hyperthermia, and magnetic hyperthermia. The reviewed studies show that high-valence metal MOFs mainly provide stable and modifiable frameworks, whereas transition-metal, magnetic, and multimetallic MOFs contribute to redox regulation, ROS generation, magnetic response, and microwave energy dissipation. Beyond localized heat generation, MOF-based platforms enhance therapeutic efficacy by combining hyperthermia with chemotherapy, chemodynamic therapy, metabolic intervention, immunotherapy, and imaging guidance. These integrated strategies help overcome incomplete ablation, thermotolerance, oxidative stress resistance, and tumor recurrence. However, clinical translation is still limited by insufficient standardization, uncertain degradation behavior, metal-ion safety, and inadequate thermal dose control. Future development should emphasize mechanism-oriented design, controllable composition, long-term biosafety, and image-guided thermal regulation to advance MOF-based hyperthermia toward precise and clinically relevant cancer therapy. Full article

(This article belongs to the Special Issue Emerging Nanomaterials and Nanotechnologies for Biomedical and Related Applications)

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20 pages, 2626 KB

Open AccessEditor’s ChoiceArticle

Surgical Video Understanding with Alignment-Preserving Temporal Adaptation and Action Triplet Text Alignment

by Taiyo Ikeido, Ren Togo, Takahiro Ogawa, Taku Sugiyama, Saseem Poudel, Hiroyuki Sugimori, Minghui Tang, Feng Han, Hidenori Koyano, Kenji Hirata, Kohsuke Kudo and Miki Haseyama

Bioengineering 2026, 13(6), 640; https://doi.org/10.3390/bioengineering13060640 - 29 May 2026

Viewed by 651

Abstract

Surgical workflow understanding requires recognizing procedural phases and fine-grained activities from long-horizon videos, yet acquiring dense annotations for surgical video analysis is costly and requires medical expertise. To address this challenge, we present a text-guided and annotation-efficient framework for surgical video understanding based [...] Read more.

Surgical workflow understanding requires recognizing procedural phases and fine-grained activities from long-horizon videos, yet acquiring dense annotations for surgical video analysis is costly and requires medical expertise. To address this challenge, we present a text-guided and annotation-efficient framework for surgical video understanding based on a frozen surgical vision–language-pretrained (VLP) encoder and a lightweight temporal adapter. The frozen SurgVLP image encoder provides frame-level visual embeddings, and the temporal adapter aggregates them into clip-level representations while preserving compatibility with the pretrained visual–text embedding space. We evaluate the proposed framework on CholecT50 using text-guided prototype matching for phase recognition and few-shot triplet recognition. Experiments show that temporal adaptation improves phase recognition while preserving the pretrained SurgVLP embedding space. In particular, among the evaluated methods, the proposed Text Contrastive method with rich phase prompts achieves the highest phase recognition performance, outperforming the phase-only baseline. Furthermore, the proposed framework enables classifier-free few-shot triplet recognition in the frozen text space without training a dedicated triplet classifier. These results suggest that effective surgical video understanding under limited annotation depends not only on temporal adaptation but also on preserving alignment with the pretrained text space and using semantically informative text prompts. Full article

(This article belongs to the Section Biosignal Processing)

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22 pages, 5025 KB

Open AccessEditor’s ChoiceArticle

Trunk Impact Conditions in Mountain Biking: Biomechanical Insights for Back Protector Evaluation

by Sophie Bonte, Arsène Thouzé, Wei Wei, Pierre-Jean Arnoux, Lionel Thollon and Nicolas Bailly

Bioengineering 2026, 13(6), 636; https://doi.org/10.3390/bioengineering13060636 - 29 May 2026

Viewed by 547

Abstract

Background: Mountain biking is increasingly popular but carries a large risk of severe trunk and spinal injuries. However, realistic crash scenarios for back protector design remain poorly characterized. This study aimed to define trunk impact conditions during mountain biking crashes. Methods: A multi-body [...] Read more.

Background: Mountain biking is increasingly popular but carries a large risk of severe trunk and spinal injuries. However, realistic crash scenarios for back protector design remain poorly characterized. This study aimed to define trunk impact conditions during mountain biking crashes. Methods: A multi-body model for mountain bike accident reconstruction was developed, and its kinematics were validated against real-world crash video footage. The model was then used to assess the influence of initial conditions (speed, slope, crash cause, etc.) on trunk impact kinematics (velocities, forces, pseudo-energy) and spinal loading indicators during forward crashes. Results: Across 288 simulated crashes, the median normal trunk impact velocity (4.61 m/s) and pseudo-energy (48 J) aligned with current test standards, while substantial tangential (5.97 m/s) and rotational (4.90 rad/s) components were also observed. Three main impact types emerged: head–thorax impacts (43.5%), involving a head impact followed by chest impact (Vn: 5.42 m/s, Emax: 59 J); tumbling (25.1%), featuring a head impact followed by back impact (Vn: 3.98 m/s, Emax: 57 J); and overflip–back impacts (20.7%), involving direct back contact (Vn: 3.35 m/s, Emax: 47 J). Conclusion: This study’s results define trunk impact conditions during MTB crashes, informing on realistic boundary conditions for testing and designing back protectors. Full article

(This article belongs to the Special Issue Sports Biomechanics and Injury Rehabilitation)

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15 pages, 1493 KB

Open AccessEditor’s ChoiceArticle

Thermodynamics of Binding Between Adeno-Associated Viruses and Heparin in Bulk and at Interfaces via Isothermal Titration Calorimetry

by Elizabeth Adeogun, Jude C. Obijiaku, Ronny Horax, Kayla E. Daugherty, Joshua Sakon, Xianghong Qian, Barbara Knutson, Stephen E. Rankin and Karthik Nayani

Bioengineering 2026, 13(6), 631; https://doi.org/10.3390/bioengineering13060631 - 28 May 2026

Viewed by 595

Abstract

Adeno-associated viruses (AAVs) have emerged as promising vectors for gene therapy due to their non-pathogenic nature and ability to transduce various cell types efficiently. In recent years, there has been an increasing effort to optimize the production and purification of AAV to support [...] Read more.

Adeno-associated viruses (AAVs) have emerged as promising vectors for gene therapy due to their non-pathogenic nature and ability to transduce various cell types efficiently. In recent years, there has been an increasing effort to optimize the production and purification of AAV to support clinical applications; however, challenges exist in affinity ligand design, synthesis, and characterization. Understanding the binding interactions of these viruses with functional molecules is pivotal for the development of affinity-based separation methods of AAVs. Classical methods to measure thermodynamic parameters such as Isothermal Titration Calorimetry (ITC) are challenging to employ in these scenarios, as the concentrations of the viral titers are significantly lower than those used in binding experiments with small biomolecules. Here, we present design principles that enable ITC-based determination of binding interactions between AAV2 and heparin. We observe increasing binding affinity with increasing molecular weight of heparin. We also elucidate the binding stoichiometry between AAV2 and heparins of varying molecular weights. Additionally, we report on the impact of buffer conditions and pH values on AAV2–heparin binding properties. Lastly, we also present the binding affinities and thermodynamic properties of interactions between the two species with heparin immobilized onto surfaces, namely, silica nanoparticles, as surface immobilization of the ligand is a common pathway for affinity-based separations. Overall, our results may provide key information for optimization of AAV-ligand binding protocols that are an essential step toward optimizing AAV capture and immobilization methods. Full article

(This article belongs to the Section Biochemical Engineering)

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23 pages, 7336 KB

Open AccessEditor’s ChoiceArticle

Biomechanical Behavior of Composite Bone–Osteosynthesis Constructs in Complex Proximal Humerus Fractures: A Synergistic Experimental and Finite Element Approach

by Andrei Scripcaru, Vasile Iulian Antoniac, Mădălina Maria Diac, Mihnea Theodor Sîrbu, Tatiana Iov, Veronica Scripcaru, Simona Irina Damian, Diana Bulgaru Iliescu, Norin Forna and Paul-Dan Sîrbu

Bioengineering 2026, 13(6), 625; https://doi.org/10.3390/bioengineering13060625 - 27 May 2026

Viewed by 715

Abstract

This study evaluates the mechanical behavior of bone-implant assemblies used in treating complex proximal humerus fractures, a clinical challenge due to the anisotropic nature of bone and variability in patient-specific conditions. The aim of this study was to compare the stability and stress [...] Read more.

This study evaluates the mechanical behavior of bone-implant assemblies used in treating complex proximal humerus fractures, a clinical challenge due to the anisotropic nature of bone and variability in patient-specific conditions. The aim of this study was to compare the stability and stress distribution of three fixation methods: polyaxial locking plates, monoaxial locking plates, and intramedullary nails. Using 4th-generation composite humerus models, a four-part fracture (Neer IV) was simulated. The assemblies underwent axial compression testing using a universal testing machine, complemented by finite element analysis (FEA) and stereomicroscopy. The results indicate that while both plate types exhibited similar mechanical behavior—with stiffness values around 113–115 N/mm and failure initiated by plastic deformation of the implant—the intramedullary nail configuration demonstrated higher stiffness values under the tested experimental conditions (1084 N/mm), approximately 9.5 times higher than that of the plates. However, the nail assembly failed through brittle fracture of the bone rather than implant deformation. We conclude that while the intramedullary nail configuration demonstrated higher stiffness under the tested experimental conditions, its performance is heavily dependent on bone quality. In contrast, locking plates may provide a more gradual load-transfer behavior by transferring a greater proportion of the mechanical load to the implant, potentially making them more suitable for osteoporotic bone conditions, where reducing excessive stress concentration within the bone tissue may be beneficial. Full article

(This article belongs to the Special Issue Orthopedic and Trauma Biomechanics)

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15 pages, 5759 KB

Open AccessEditor’s ChoiceArticle

A Probabilistic Three-Dimensional Finite Element Model of a Cemented Hip Implant Failure Under Aseptic Loosening: A Case-Based Probabilistic Framework

by Daniel Truong, Scott J. Hazelwood, Jonathan Fow and Lanny V. Griffin

Bioengineering 2026, 13(6), 623; https://doi.org/10.3390/bioengineering13060623 - 27 May 2026

Viewed by 451

Abstract

Background: Hip implant fractures are rare, yet difficult to correct once they occur. For cemented implants, fracture is often associated with increased stresses at the implant stem when proximal regions of the implant have debonded. While deterministic analyses offer predictive power by using [...] Read more.

Background: Hip implant fractures are rare, yet difficult to correct once they occur. For cemented implants, fracture is often associated with increased stresses at the implant stem when proximal regions of the implant have debonded. While deterministic analyses offer predictive power by using averages for model inputs, averages fail to capture the variability inherent in device manufacturing and musculoskeletal biology. This study developed a probabilistic finite element model of a debonded hip implant to better account for some of these variabilities to predict the most likely failure mode. The hypothesis was that fatigue would be more likely to occur than overloading. Methods and Materials: Monte Carlo sampling generated 1000 simulations varying the material elastic modulus (implant, cement, and bone) and loading magnitude at stance phase of the gait. The resultant distributions of maximum von Mises stress at the stem were compared to distributions for failure properties in the literature. Results: The analysis found the likelihood of the implant failing due to overloading was remote. In contrast, fatigue failure had a 99.4% chance of occurring. Fracture mechanics predicted that the debonded implant would reach critical flaw length between 1.8 and 26.4 months, with a mean of 7.2 months. Conclusions: The results show good agreement with the findings of the case study the model was based on, particularly in predicting the location of failure and fatigue life. The results of this study provide a framework for developing future decision-making tools that ultimately may assist clinicians in deciding when interventions are necessary to minimize the risk of implant or periprosthetic fracture. Full article

(This article belongs to the Special Issue Advances in Biomaterials and Evaluation for Orthopaedic Implants)

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12 pages, 13892 KB

Open AccessEditor’s ChoiceArticle

The Use of Osteo-Inductive 3D-Printed Scaffolds Covered with a Pleiotrophin Peptide for Bone Defects: An In Vivo Experimental Study

by Dimitrios Tsoumanis, Emilios E. Pakos, Ioannis Gkiatas, Ioannis Gelalis, Anna Batistatou, Evangelia Lampri, Despoina Deligianni, Evangelia Papadimitriou, Dimitrios Fotiadis and Anastasios Korompilias

Bioengineering 2026, 13(6), 608; https://doi.org/10.3390/bioengineering13060608 - 24 May 2026

Viewed by 902

Abstract

The present study investigated the effect of a 3D-printed nanocomposite scaffold on bone healing in vivo. The scaffolds used were made from the bioresorbable thermoplastic polycaprolactone polymer, blended with Multi-Walled Carbon Nanotubes functionalized with chitosan, and manufactured with a rectilinear infill pattern and [...] Read more.

The present study investigated the effect of a 3D-printed nanocomposite scaffold on bone healing in vivo. The scaffolds used were made from the bioresorbable thermoplastic polycaprolactone polymer, blended with Multi-Walled Carbon Nanotubes functionalized with chitosan, and manufactured with a rectilinear infill pattern and interconnected pores of 500 μm in size. The study included three groups of 10 Wistar rats, in which a 2 mm bone defect was created in the middle of the right femur. In the scaffold/peptide group, the gap was filled with the scaffold loaded with a peptide corresponding to human pleiotrophin amino acids 48-56 (PTN_48-56), and the fracture was stabilized with a 12 mm K-wire as an intramedullary nail. In the scaffold group, the scaffold did not contain the peptide, and in the control group, the bone defect was stabilized without the use of a scaffold. Radiological examination revealed that bone healing was achieved on average in 6.6 weeks in the scaffold/peptide group, 7.2 weeks in the scaffold group, and 8.1 weeks in the control group. Histopathological examination performed 2 weeks postoperatively showed that angiogenesis in the scaffold/peptide group was 1.5 times higher than in the scaffold group and 2.5 times higher than in the control group. In conclusion, our osteo-inductive 3D-printed scaffold covered with PTN_48-56 is a promising option for accelerating bone defect healing. Full article

(This article belongs to the Special Issue Advanced Technologies for Orthopedic Repair and Regeneration)

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20 pages, 5525 KB

Open AccessEditor’s ChoiceArticle

Predictions of Oncotype DX^® High-Risk Classification Using Magnetic Resonance Imaging-Based Intratumoral Heterogeneity

by Sung Joon Park, Won Hwa Kim, Jaeil Kim, Taewoo Kang, Ji-Young Park, Byeongju Kang, Joon Suk Moon, Ho Yong Park, Hye Jung Kim and Jeeyeon Lee

Bioengineering 2026, 13(6), 611; https://doi.org/10.3390/bioengineering13060611 - 24 May 2026

Viewed by 640

Abstract

The Oncotype DX^® 21-gene recurrence score (RS) guides adjuvant chemotherapy decisions in estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2−) breast cancer, yet requires invasive tissue sampling and involves substantial costs. This study evaluated intratumoral tumor ecological diversity (iTED), a habitat [...] Read more.

The Oncotype DX^® 21-gene recurrence score (RS) guides adjuvant chemotherapy decisions in estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2−) breast cancer, yet requires invasive tissue sampling and involves substantial costs. This study evaluated intratumoral tumor ecological diversity (iTED), a habitat imaging approach, as a non-invasive complement for predicting Oncotype DX^® high-risk classification (RS > 25). This retrospective multi-center study included 312 patients with ER+/HER2− invasive breast cancer who underwent Oncotype DX^® testing (development: n = 168; external validation: n = 144). The iTED framework employed superpixel-based habitat determination using Gaussian mixture models on pretreatment dynamic contrast-enhanced MRI. Four predictive models were compared: clinical, conventional whole-tumor radiomics (C-radiomics), iTED, and combined (Clinical + iTED). The iTED model achieved higher discriminative performance compared with C-radiomics in both development (area under the curve [AUC]: 0.868 ± 0.068 vs. 0.730 ± 0.112) and external validation (AUC: 0.811 vs. 0.587) sets. The combined model further improved performance (development AUC: 0.908 ± 0.043; external AUC: 0.889). Habitat imaging-based iTED features achieved numerically higher performance than conventional radiomics in predicting Oncotype DX^® high-risk classification. These findings suggest the potential of iTED as a non-invasive imaging biomarker to support molecular testing in clinical decision-making. Full article

(This article belongs to the Special Issue AI and Data Science in Biomedicine: Powering the Next Generation of Diagnostics and Therapies)

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29 pages, 5506 KB

Open AccessEditor’s ChoiceArticle

Ensuring Good Transferability from Pilot- to Large-Scale Optimized Biotech Bubble Column Designs

by Carolin Link, Jason Bromley, Michael Martin and Ralf Takors

Bioengineering 2026, 13(5), 579; https://doi.org/10.3390/bioengineering13050579 - 19 May 2026

Viewed by 538

Abstract

Scaling biotechnology processes such as gas fermentation remains resource- and time-intensive, both experimentally and in modeling. To improve the efficiency of reactor geometry optimization, we evaluated the transferability of findings from pilot-scale (950 L) simulations to industrial-scale simulations (950 m³). At [...] Read more.

Scaling biotechnology processes such as gas fermentation remains resource- and time-intensive, both experimentally and in modeling. To improve the efficiency of reactor geometry optimization, we evaluated the transferability of findings from pilot-scale (950 L) simulations to industrial-scale simulations (950 m³). At constant geometric ratios and aeration (vvm) across scales, highly similar flow patterns were observed, especially in airlift reactors. Reactor design enhancements at the pilot scale were transferable to the industrial scale, delivering improvements of up to 17% for k_La. Surprisingly, the commercial simulation resulted in an order-of-magnitude-higher gas holdup and k_La than the pilot, owing to a longer bubble residence time in the taller vessel. Thus, transferability can be further enhanced by enforcing constant superficial gas velocity between scales. This leads to more similar CO transfer rates and regime distributions inside the tank but will challenge reaching sufficient mass transfer for industrial applications. Full article

(This article belongs to the Special Issue Strategies for Microbial Bioprocess Optimization)

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12 pages, 19658 KB

Open AccessEditor’s ChoicePerspective

Polyetheretherketone (PEEK) in Cranial Vault Reconstruction: A Review of Alloplastic Materials, Clinical Performance, and Institutional Experience

by Christine F. Johansen and Shai M. Rozen

Bioengineering 2026, 13(5), 567; https://doi.org/10.3390/bioengineering13050567 - 16 May 2026

Viewed by 924

Abstract

Cranial vault reconstruction is a critical component of care following trauma, decompressive craniectomy, infection, or oncologic resection. Large and complex cranial defects present unique reconstructive challenges, as autologous reconstruction may be limited by donor availability, contour mismatch, and long-term resorption. Consequently, alloplastic materials [...] Read more.

Cranial vault reconstruction is a critical component of care following trauma, decompressive craniectomy, infection, or oncologic resection. Large and complex cranial defects present unique reconstructive challenges, as autologous reconstruction may be limited by donor availability, contour mismatch, and long-term resorption. Consequently, alloplastic materials have become central to contemporary cranioplasty. Advances in imaging, computer-aided design/manufacturing (CAD/CAM), and three-dimensional workflows have enabled increasingly accurate patient-specific reconstruction with improved operative efficiency. This narrative perspective summarizes the evolution and clinical application of commonly used alloplastic materials in cranial vault reconstruction, including titanium, polymethylmethacrylate (PMMA), and hydroxyapatite (HA), with a focused discussion of polyetheretherketone (PEEK). We discuss the design rationale, material properties, and clinical performance of PEEK, emphasizing bone-mimicking elasticity, radiolucency, and compatibility with CAD/CAM workflows. Institutional experience is integrated to contextualize durability, aesthetic restoration, neurologic improvement, infection management, and technical considerations that influence outcomes. Overall, PEEK represents a versatile option for large and complex cranial reconstruction by combining favorable mechanical performance with patient-specific design capability. Continued advances in biomaterials and surgical planning, coupled with rigorous long-term outcome evaluation, will further refine material selection and optimize reconstructive outcomes in cranial vault reconstruction. Full article

(This article belongs to the Special Issue Biomedical Engineering for Facial Reconstruction)

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12 pages, 3741 KB

Open AccessEditor’s ChoiceTechnical Note

Sustainable Production of Dental and Orthodontic 3D Models Through Fused Granular Fabrication of Recycled Polymers

by Jens Kruse, Malte Stonis, Julia Barasinski, Florian Konstantin Stangl and Hisham Sabbagh

Bioengineering 2026, 13(5), 558; https://doi.org/10.3390/bioengineering13050558 - 15 May 2026

Viewed by 712

Abstract

Sustainable production in dental and orthodontic 3D printing has gained increasing attention due to environmental concerns and the need for cost-effective and resource-saving solutions. This study presents a proof of concept for using recycled polymers and fused granular fabrication (FGF) in a closed-loop [...] Read more.

Sustainable production in dental and orthodontic 3D printing has gained increasing attention due to environmental concerns and the need for cost-effective and resource-saving solutions. This study presents a proof of concept for using recycled polymers and fused granular fabrication (FGF) in a closed-loop 3D printing approach, omitting intermediate filament manufacturing. A desktop 3D printer served as the kinematic platform and was modified with a pellet-based extruder to directly process recycled polyethylene terephthalate glycol (PETG) flakes, obtained by shredding previously printed PETG parts, into dental models. Dimensional accuracy was evaluated using optical 3D scanning analysis. The results indicate that models produced from recycled PETG are, in principle, suitable for dental and orthodontic applications within the investigated scope. This technical note provides initial evidence supporting the integration of recycled thermoplastics into dental and orthodontic model fabrication as part of sustainable additive manufacturing workflows. Potential pathways for workflow integration in clinical and laboratory environments, as well as directions for future research, are outlined, including the optimization of printing parameters and process stability. The main technical challenges were unreliable feedstock flow, causing bridging and jamming, while thermal creep from insufficient inlet cooling promoted premature softening of the flakes, causing torque spikes and unstable feeding. Full article

(This article belongs to the Special Issue Three-Dimensional Printing in Modern Dentistry: State of the Art, Benefits and Future Prospects)

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23 pages, 6369 KB

Open AccessEditor’s ChoiceArticle

Effective Recellularization Using Mesenchymal Stem Cell Monoculture for Next-Generation Heart Valves

by So Young Kim, Ja-Kyoung Yoon, Serin Kim, Sunhi Ko, Yerin Shin, Gi Beom Kim, Hong-Gook Lim and Yong Jin Kim

Bioengineering 2026, 13(5), 546; https://doi.org/10.3390/bioengineering13050546 - 11 May 2026

Viewed by 1637

Abstract

Objective: Effectively eliminating xenoimmunogenicity and achieving recellularization in cardiac xenografts remains a critical challenge in developing an ideal implantable xenograft. We have previously demonstrated that the removal of major antigens, including Galα1-3Gal (α-Gal) epitope and non-human sialic acid N-glycolylneuraminic acid (Neu5Gc), using α-galactosidase [...] Read more.

Objective: Effectively eliminating xenoimmunogenicity and achieving recellularization in cardiac xenografts remains a critical challenge in developing an ideal implantable xenograft. We have previously demonstrated that the removal of major antigens, including Galα1-3Gal (α-Gal) epitope and non-human sialic acid N-glycolylneuraminic acid (Neu5Gc), using α-galactosidase and peptide N-glycosidase F (PNGase-F), enables a synergistic effect with decellularization, significantly reducing the expression of carbohydrate-binding lectins without altering the biomechanical properties of the graft. The aim of this study was to establish an effective method for in vitro recellularization by seeding human mesenchymal stem cells (MSCs) on decellularized cardiac xenografts that had undergone optimal xenoantigen removal using α-galactosidase and PNGase-F. Additionally, this study aimed to evaluate the potential for in vivo recellularization. Methods: Decellularized porcine pericardium scaffolds treated with both enzymes were further modified by forming a fibrin mesh on their surface and within their structure, followed by the attachment of heparin and human vascular endothelial growth factor to the mesh. Subsequently, the scaffolds were seeded with human adipose tissue-derived stem cells for 8 weeks. In vitro recellularization, differentiation, and extracellular matrix remodeling of decellularized and enzyme-treated xenografts were assessed using vimentin, calponin, fibronectin, CD31, VWF, and phalloidin staining. To evaluate the potential for in vivo recellularization, decellularized glutaraldehyde-crosslinked xenografts with anticalcification treatments were seeded with rat bone marrow MSCs and implanted into rats subcutaneously to evaluate cell infiltration and calcification via histology, von Kossa staining, and micro-computed tomography. Results: In decellularized xenografts treated with both enzymes, stronger signals were detected and mesenchymal cell infiltration into the tissue was significantly faster, leading to accelerated recellularization. This recellularization process was more pronounced as time went on, with greater cell infiltration and evidence of cell differentiation. An in vivo study showed that decellularization and anticalcification treatments revealed stronger vimentin staining in histological analysis. The recellularization for our biocompatible scaffolds exhibited a lower degree of calcification compared to the non-recellularized tissue. Conclusions: We successfully developed major xenoantigen-free scaffolds by demonstrating the safety and synergistic effect of α-galactosidase and PNGase-F treatments and proved, for the first time, the effectiveness of recellularization using a human MSC monoculture on xenoantigen-free scaffolds. Furthermore, there was potential for in vivo recellularization of our biocompatible scaffolds seeded with MSCs. Full article

(This article belongs to the Section Regenerative Engineering)

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20 pages, 1071 KB

Open AccessEditor’s ChoiceReview

Bone Tissue Engineering: Scaffold Design Principles, Biomaterial Advances, and Strategies for Functional Regeneration and Clinical Translation

by Naznin Sultana

Bioengineering 2026, 13(5), 514; https://doi.org/10.3390/bioengineering13050514 - 29 Apr 2026

Cited by 3 | Viewed by 2043

Abstract

Bone is a hierarchically organized composite material with unique mechanical properties and an intrinsic regenerative capacity that conventional repair strategies, including autografts, allografts, xenografts, and metallic or ceramic implants, fail to fully replicate due to donor scarcity, immunogenicity, mechanical mismatch, and poor long-term [...] Read more.

Bone is a hierarchically organized composite material with unique mechanical properties and an intrinsic regenerative capacity that conventional repair strategies, including autografts, allografts, xenografts, and metallic or ceramic implants, fail to fully replicate due to donor scarcity, immunogenicity, mechanical mismatch, and poor long-term integration. Bone tissue engineering (TE) offers a biologically informed alternative by integrating osteoconductive scaffolds, osteogenic progenitor cells, and osteoinductive signaling molecules into a unified regenerative framework. Unlike existing reviews that evaluate these components in isolation, this review provides a mechanistically integrated analysis that repositions scaffold design as a biologically instructive platform whose topography, stiffness, porosity, and surface chemistry collectively govern cell adhesion, mechanotransduction, osteogenic differentiation, and extracellular matrix remodeling. Critically, it moves beyond cataloging materials and fabrication approaches to evaluate how specific scaffold features drive biological outcomes and to identify frequently understated limitations, including polymer-ceramic degradation kinetics and the inadequacy of small-animal models for clinical translation. By synthesizing advances in biomaterials, additive manufacturing, and smart scaffold technologies within this integrative framework, this review provides researchers and clinicians with a structured framework for evaluating emerging strategies and prioritizing future directions in functional bone regeneration. Full article

(This article belongs to the Special Issue Next-Generation Biomaterials and Regenerative Strategies for Precision Tissue Engineering)

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13 pages, 1752 KB

Open AccessEditor’s ChoiceArticle

Effect of Alumina Airborne-Particle Abrasion Followed by Plasma Treatment on Bond Strength of Dental PEEK to MMA-Based Luting Systems

by Taro Mukaibo, Takafumi Watanabe, Ayako Miura, Kanna Saimoto, Misaki Matsuo, Hiromichi Ogusu, Chihiro Masaki and Hiroshi Ikeda

Bioengineering 2026, 13(5), 507; https://doi.org/10.3390/bioengineering13050507 - 28 Apr 2026

Viewed by 871

Abstract

Poly (ether ether ketone) (PEEK) has attracted increasing attention for dental applications because of its favorable mechanical properties, physicochemical stability, and biocompatibility. However, its inherently poor bonding characteristics remain a major limitation in clinical practice. This study investigated the effect of sequential alumina [...] Read more.

Poly (ether ether ketone) (PEEK) has attracted increasing attention for dental applications because of its favorable mechanical properties, physicochemical stability, and biocompatibility. However, its inherently poor bonding characteristics remain a major limitation in clinical practice. This study investigated the effect of sequential alumina airborne-particle abrasion (sandblasting) followed by plasma treatment on the bonding performance of methyl methacrylate (MMA)-based luting systems to dental CAD-CAM PEEK. PEEK specimens were prepared as plates and divided into four surface-treatment groups: untreated, airborne-particle abraded, plasma-treated, and airborne-particle abraded followed by plasma treatment. Surface characteristics were evaluated using SEM–EDX analysis and surface roughness measurements, and surface wettability was assessed by contact angle measurements using primers from two MMA-based luting systems (Beautylink [BL] and Super-Bond [SB]). Shear bond strength (SBS) between treated PEEK and each luting system was determined after 24 h of water storage (initial) and after 20,000 thermocycles (aged). Airborne-particle abrasion significantly increased surface roughness, whereas plasma treatment enhanced surface wettability without altering roughness. The combined treatment resulted in the highest surface roughness and the lowest contact angles and demonstrated superior or comparable SBS compared with the single treatments. After aging, the combined treatment significantly improved bonding durability. These findings indicate that airborne-particle abrasion followed by plasma treatment enhances the bonding performance and durability of MMA-based luting systems to PEEK. Full article

(This article belongs to the Special Issue Dental Biomaterials: Current and Future Perspectives)

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19 pages, 4117 KB

Open AccessEditor’s ChoiceArticle

Automatic Personal Identification Using a Single MRI Slice

by Andreas Heinrich

Bioengineering 2026, 13(5), 494; https://doi.org/10.3390/bioengineering13050494 - 24 Apr 2026

Cited by 1 | Viewed by 1316

Abstract

Identification of unknown individuals is challenging, and radiological imaging databases provide rich anatomical information for automated recognition. This study evaluated whether a single routine magnetic resonance imaging (MRI) slice contains sufficient person-specific features to identify individuals in large databases. It analyzed 11,078 head [...] Read more.

Identification of unknown individuals is challenging, and radiological imaging databases provide rich anatomical information for automated recognition. This study evaluated whether a single routine magnetic resonance imaging (MRI) slice contains sufficient person-specific features to identify individuals in large databases. It analyzed 11,078 head MRI examinations from 5770 individuals (age 52 ± 18 years, 2714 men) acquired between 2002 and 2025. For identification, 112 individuals were randomly selected across eight 10-year age groups, and one slice from four anatomical regions was extracted. The remaining 10,966 MRI examinations with 247,804 slices formed the reference database. Distinctive anatomical features were automatically extracted using computer vision (CV), and the identification rate was evaluated by rank. Using a single MRI slice, the identification rate at rank 1 reached 96% (107/112) for the best-performing region, the maxillary sinus, among 5770 potential identities. Across all regions, the rank 1 identification rate ranged from 91% to 96%; combining them increased rank 1 and 10 identification rates to 98% (110/112) and 99% (111/112). Identification rate remained stable over several years, with only two cases showing reduced rank 1 performance, likely due to age-related morphological changes. A single MRI slice contains stable, individualized features sufficient for reliable identification in large databases, supporting automated CV-based personal identification across years. Full article

(This article belongs to the Special Issue Next-Generation Biosignal Engineering: AI-Driven Diagnostics, Prosthetic Interfaces and Multimodal Physiological Sensing)

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25 pages, 29765 KB

Open AccessEditor’s ChoiceReview

Engineering Organ-on-a-Chip Systems for Cancer Immunotherapy: Strategies and Assay Integration

by Jie Wang and Zongjie Wang

Bioengineering 2026, 13(5), 492; https://doi.org/10.3390/bioengineering13050492 - 23 Apr 2026

Viewed by 1648

Abstract

Translating preclinical findings into effective clinical cancer immunotherapies remains a major challenge, mainly because conventional in vitro and animal models often fail to capture the complexity, dynamics, and species-specific features of human immune responses. Organ-on-a-chip (OoC) technologies that combine engineered tissue architectures with [...] Read more.

Translating preclinical findings into effective clinical cancer immunotherapies remains a major challenge, mainly because conventional in vitro and animal models often fail to capture the complexity, dynamics, and species-specific features of human immune responses. Organ-on-a-chip (OoC) technologies that combine engineered tissue architectures with precisely controlled microfluidic transport provide human-relevant microphysiological platforms for mechanistic studies of immune–tumor interactions and evaluation of therapeutic efficacy and immunotoxicity under defined microenvironmental conditions. However, immune responses involve time-dependent and interconnected processes, including immune cell trafficking, cytokine programs, metabolic shifts, and cytolysis, that are not adequately resolved by static or endpoint assays. Engineering immune-competent OoC systems therefore requires coordinated design of platform architectures, immune cell incorporation strategies, and integrated measurement workflows capable of capturing dynamic and state-dependent responses. In this review, we summarize engineering strategies for building immune-competent OoC platforms for cancer immunotherapy, focusing on platform architectures, immune cell incorporation methods, and fit-for-purpose assay workflows. Emphasis is placed on embedded sensing modalities (e.g., cytokine, oxygen, and impedance readouts) that provide valuable kinetic and state-variable data. Finally, we discuss key translational challenges, including reproducibility, standardization, and benchmarking, and outline near-term priorities to accelerate the adoption of immune-competent OoC systems in immunotherapy research and development. Full article

(This article belongs to the Special Issue Advanced Microfluidics for Biomedical Engineering: From Single Cell Analysis to Organ on a Chip)

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5 pages, 152 KB

Open AccessEditor’s ChoiceEditorial

Recent Findings and Developments in Spine Biomechanics

by Christian Liebsch

Bioengineering 2026, 13(4), 482; https://doi.org/10.3390/bioengineering13040482 - 21 Apr 2026

Viewed by 925

Abstract

As the central musculoskeletal element of the human body, the spine simultaneously enables trunk movement, upright posture, and load transfer from the upper to the lower body [...] Full article

(This article belongs to the Special Issue Spine Biomechanics)

11 pages, 2008 KB

Open AccessEditor’s ChoiceBrief Report

Nano-Enhanced Optical Delivery of Multi-Characteristic Opsin Gene for Spinal Optogenetic Modulation of Pain

by Darryl Narcisse, Robert Benkowski, Matthew Dwyer and Samarendra Mohanty

Bioengineering 2026, 13(4), 479; https://doi.org/10.3390/bioengineering13040479 - 20 Apr 2026

Cited by 1 | Viewed by 687

Abstract

Optogenetic modulation employs light-sensitive proteins known as opsins to regulate cellular activity. A unique therapeutic application of this technique involves modulating pain perception by selectively targeting neural pathways within the spinal cord. Multi-Characteristic Opsin (MCO) represents an innovative optogenetic actuator capable of activation [...] Read more.

Optogenetic modulation employs light-sensitive proteins known as opsins to regulate cellular activity. A unique therapeutic application of this technique involves modulating pain perception by selectively targeting neural pathways within the spinal cord. Multi-Characteristic Opsin (MCO) represents an innovative optogenetic actuator capable of activation across a broad spectrum of light wavelengths, exhibiting a slow depolarizing phase that resembles natural photoreceptors. This study examines the current advancements in spinal optogenetic modulation utilizing MCO for pain management. Due to its high sensitivity, MCO facilitates minimally invasive, remotely controlled optogenetic modulation of spinal neurons. This approach enables the regulation of extensive spatial regions, provided the MCO channel receives sufficient light intensity to surpass the activation threshold. Nano-enhanced optical delivery (NOD) successfully transfected spinal neurons with the GAD67-MCO2-mCherry construct, as confirmed by membrane-localized mCherry fluorescence with DAPI-labeled nuclei. Using this platform, 5 Hz spinal optogenetic stimulation produced a significant reduction in formalin-evoked pain behaviors, demonstrating frequency-specific modulation of spinal pain circuits. Neither 2 Hz nor 10 Hz stimulation yielded comparable analgesic effects, underscoring the importance of precise stimulation parameters. The therapeutic impact also depended on transfection efficiency: reducing the fGNR–plasmid concentration diminished MCO expression and weakened the analgesic response. Together, these results show that effective spinal optogenetic pain modulation requires both optimal stimulation frequency and robust gene delivery. Full article

(This article belongs to the Section Nanobiotechnology and Biofabrication)

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19 pages, 679 KB

Open AccessEditor’s ChoiceReview

Biomechanical Factors and Prevention Strategies for Sports-Related Muscle Injuries: A Narrative Review

by Catalin Ionite, Lucian Indrei, Andrei Gheorghiță, Bogdan Caba, Marius Turnea, Irina Duduca, Cezar Mucileanu, Iustina Condurache and Mariana Rotariu

Bioengineering 2026, 13(4), 473; https://doi.org/10.3390/bioengineering13040473 - 17 Apr 2026

Viewed by 2155

Abstract

Sports-related muscle injuries represent a major challenge in both recreational and professional sports, accounting for a substantial proportion of time-loss injuries and frequently leading to recurrent episodes. The aim of this narrative review was to analyze the biomechanical and neuromuscular mechanisms involved in [...] Read more.

Sports-related muscle injuries represent a major challenge in both recreational and professional sports, accounting for a substantial proportion of time-loss injuries and frequently leading to recurrent episodes. The aim of this narrative review was to analyze the biomechanical and neuromuscular mechanisms involved in the occurrence of muscle injuries and to synthesize evidence-based prevention strategies reported in the scientific literature. The literature search was conducted in the Web of Science database using the keyword “muscle injury prevention”, focusing on studies published between 2010 and 2025. The analyzed literature indicates that muscle injuries are strongly associated with eccentric contractions at long muscle lengths, neuromuscular fatigue, strength imbalances, impaired lumbopelvic stability, and inadequate load management. Preventive strategies based on biomechanical principles, particularly eccentric strength training, neuromuscular training programs, and core stability exercises, have demonstrated consistent effectiveness in reducing injury incidence and recurrence rates across multiple sports disciplines. In addition, emerging technological approaches, including wearable sensors and machine learning models, show promising potential for injury risk prediction and individualized prevention strategies. Full article

(This article belongs to the Special Issue Orthopedic and Trauma Biomechanics)

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21 pages, 2144 KB

Open AccessEditor’s ChoiceArticle

ERG-Graph: Graph Signal Processing of the Electroretinogram for Classification of Neurodevelopmental Disorders

by Luis Roberto Mercado-Diaz, Javier O. Pinzon-Arenas, Paul A. Constable, Irene O. Lee, Lynne Loh, Dorothy A. Thompson and Hugo F. Posada-Quintero

Bioengineering 2026, 13(4), 446; https://doi.org/10.3390/bioengineering13040446 - 11 Apr 2026

Cited by 1 | Viewed by 1500

Abstract

Objective biomarkers for neurodevelopmental disorders remain an unmet clinical need. The electroretinogram (ERG), a non-invasive recording of the retinal response to light, has shown promise as a physiological marker for autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD), yet existing classification approaches [...] Read more.

Objective biomarkers for neurodevelopmental disorders remain an unmet clinical need. The electroretinogram (ERG), a non-invasive recording of the retinal response to light, has shown promise as a physiological marker for autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD), yet existing classification approaches based on time-domain and time–frequency features achieve limited accuracy in clinically relevant multi-group scenarios. This study introduces ERG-Graph, a novel graph signal processing (GSP) framework that transforms each ERG waveform into a weighted, undirected graph through amplitude quantization and temporal-adjacency connectivity. Nine topological and spectral features, including total load centrality, clique number, algebraic connectivity, and clustering coefficient, were extracted from each graph to characterize the structural dynamics of the signal. Using light-adapted ERG recordings from 278 participants (ASD = 77, ADHD = 43, ASD + ADHD = 21, Control = 137), we evaluated these features across binary, three-group, and four-group classification scenarios using seven machine learning classifiers with 10-fold subject-wise cross-validation. The proposed ERG-Graph features achieved balanced accuracies of 0.91 (ASD vs. control, males) and 0.88 (ADHD vs. control, females). Critically, fusing ERG-Graph with time-domain features yielded a balanced accuracy of 0.81 for three-group classification (ASD vs. ADHD vs. control), representing an 11-percentage-point improvement over the previous benchmark of 0.70. Statistical analysis confirmed significant topological differences between groups (Kruskal–Wallis, p < 0.001; Cliff’s delta: large effect sizes), and SHAP analysis revealed that graph-theoretic features dominated the top-ranked predictors. These results demonstrate that graph-based topological features capture discriminative information in the ERG waveform that is inaccessible to conventional signal analysis methods, advancing the development of objective biomarkers for neurodevelopmental disorder screening. Full article

(This article belongs to the Section Biosignal Processing)

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15 pages, 8328 KB

Open AccessEditor’s ChoiceArticle

In Vitro Biofilm Formation on 3D-Printed, Milled, and Conventionally Manufactured Denture Base Resins

by Michael del Hougne, Alexander Mitzscherling, Andrea Ewald, Tatjana Schilling, Philipp Stahlhut, Uwe Gbureck and Marc Schmitter

Bioengineering 2026, 13(4), 424; https://doi.org/10.3390/bioengineering13040424 - 3 Apr 2026

Viewed by 1103

Abstract

Biofilm formation on denture base materials may contribute to oral diseases such as denture stomatitis and therefore represents an important factor in prosthodontic treatment. This in vitro study investigated biofilm formation on dental prosthetic materials manufactured by additive, subtractive, and conventional techniques. Disc-shaped [...] Read more.

Biofilm formation on denture base materials may contribute to oral diseases such as denture stomatitis and therefore represents an important factor in prosthodontic treatment. This in vitro study investigated biofilm formation on dental prosthetic materials manufactured by additive, subtractive, and conventional techniques. Disc-shaped specimens were fabricated from 3D-printed Denture Base Resin (Formlabs), milled Lucitone Digital Fit (Dentsply Sirona), and conventionally processed cold-polymerized PALAPress (Kulzer). Biofilm formation by Streptococcus mutans and Streptococcus sanguinis was assessed separately over a 21-day incubation period using crystal violet staining and photometric determination of optical density at eight predefined time points. Surface characteristics before and after microbial colonization were qualitatively evaluated by scanning electron microscopy. For S. mutans, significant material-dependent differences were observed only at selected time points, while overall biofilm accumulation remained low. In contrast, S. sanguinis exhibited pronounced and repeated differences, with milled PMMA generally showing lower biofilm accumulation compared with additively manufactured and conventionally processed materials. Overall, S. sanguinis formed significantly more biofilm than S. mutans across all materials and time points. These findings indicate that both manufacturing technique and bacterial species influence biofilm formation on denture base materials. Full article

(This article belongs to the Special Issue Advanced 3D-Printed Biomaterials in Dentistry)

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19 pages, 1477 KB

Open AccessEditor’s ChoiceArticle

Circular Approach to Biomanufacturing: Enhancing Therapeutic Protein Production Using Chum Salmon Head Peptone

by Svini Dileepa Marasinghe, Minthari Sakethanika Bandara, Somyong Lee, Young Hwa Kim, Su-Jin Lee, Dong Soo Hwang, Youngdeuk Lee, Eunyoung Jo, Tae-Yang Eom, Gun-Hoo Park and Chulhong Oh

Bioengineering 2026, 13(4), 409; https://doi.org/10.3390/bioengineering13040409 - 31 Mar 2026

Viewed by 1279

Abstract

Fish waste disposal poses significant environmental and economic challenges, limiting sustainability in the marine food industry. Hence, sustainable valorization strategies are needed to enhance resource recovery while minimizing waste. As an approach, this study aimed to evaluate the potential of converting chum salmon [...] Read more.

Fish waste disposal poses significant environmental and economic challenges, limiting sustainability in the marine food industry. Hence, sustainable valorization strategies are needed to enhance resource recovery while minimizing waste. As an approach, this study aimed to evaluate the potential of converting chum salmon (Oncorhynchus keta) head (CSH) waste into a high-value peptone for microbiological applications. Various proteolytic enzymes were screened for CSH hydrolysis, among which Protamex achieved the highest hydrolysis and recovery rates. The resulting chum salmon head peptone (CSHP) exhibited favorable characteristics, including a low average molecular mass (557 Da) and a high amino nitrogen content (4.9%), outperforming commercial animal (AP) and vegetable (VP) peptones. To assess its biotechnological potential, CSHP was evaluated as a nitrogen source for recombinant protein production and supported higher expression of human superoxide dismutase (hSOD) and human growth hormone (hGH) in Escherichia coli BL21(DE3), compared with AP, VP, and Luria–Bertani (LB) media. Furthermore, life cycle assessment revealed a substantially lower carbon footprint for CSHP production than that of conventional peptone sources. These findings suggest that CSHP is a reliable and sustainable alternative to traditional peptones, offering both therapeutic and industrial applications while contributing to marine waste reduction and circular bioeconomy strategies. Full article

(This article belongs to the Section Biochemical Engineering)

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14 pages, 1785 KB

Open AccessEditor’s ChoiceArticle

An Anaerobic Trickle-Bed Reactor Filled with Siporax™ as a Novel Approach for Biomethanation of Hydrogen and Carbon Dioxide

by Gert Hofstede, Arjan Kloekhorst, Janneke Krooneman, Kemal Koç, Kor Zwart, Folkert Faber, Jan-Peter Nap and Gert-Jan Euverink

Bioengineering 2026, 13(4), 382; https://doi.org/10.3390/bioengineering13040382 - 26 Mar 2026

Viewed by 1422

Abstract

To broaden the application of biomethanation for energy storage and renewable integration, this study investigates the performance of a trickle-bed reactor (TBR) for hydrogen (H₂) utilisation in biogas upgrading, using both pure Carbon dioxide (CO₂) and biogas-derived CO₂ [...] Read more.

To broaden the application of biomethanation for energy storage and renewable integration, this study investigates the performance of a trickle-bed reactor (TBR) for hydrogen (H₂) utilisation in biogas upgrading, using both pure Carbon dioxide (CO₂) and biogas-derived CO₂ as substrates for methane (CH₄) production. Renewable sources such as wind and solar are inherently variable, increasing the need for scalable storage solutions. Converting surplus electricity into H₂ and CH₄ via biological methanation offers an efficient and safer alternative to direct H₂ storage. By reducing CO₂ produced by biogas plants, methanogenic archaea produce CH₄, enabling H₂ valorisation and enhanced biogas yields. This study demonstrates that TBR technology can achieve CH₄ formation rates up to 15 L-CH₄/L-reactor/day under optimised conditions. Siporax carrier material supported dense biofilm formation and effective gas–liquid mass transfer, facilitating high conversion efficiency. The system showed operational robustness, with rapid recovery after prolonged idle periods and stable production rates of 10–12 L-CH₄/L/day. Wastewater was used as a realistic medium to assess reactor performance under complex, variable conditions. Reactor design focused primarily on enhancing gas–liquid mass transfer and supporting sustained microbial activity through adequate nutrient supply, ensuring sufficient buffer capacity to maintain pH stability. These results demonstrate the potential of TBR-based systems for high-rate, stable biomethanation and highlight their applicability in future energy infrastructures for integrating H₂ through decentralised biogas upgrading. Full article

(This article belongs to the Special Issue Anaerobic Biotechnologies for Energy and Resource Recovery from Waste)

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17 pages, 3325 KB

Open AccessEditor’s ChoiceArticle

Insights into Neuromuscular Function in Older Adults from Functional Data Analysis of Time-Dependent Handgrip Strength Curves

by Diana Urbano, Mário Inácio and Maria Teresa Restivo

Bioengineering 2026, 13(4), 381; https://doi.org/10.3390/bioengineering13040381 - 26 Mar 2026

Viewed by 749

Abstract

Handgrip strength (HGS) is widely used as a biomarker of muscle function and overall health in older adults. However, conventional analyses based on peak force values may overlook relevant temporal features of the HGS curve. This cross-sectional study proposes a novel [...] Read more.

Handgrip strength (HGS) is widely used as a biomarker of muscle function and overall health in older adults. However, conventional analyses based on peak force values may overlook relevant temporal features of the HGS curve. This cross-sectional study proposes a novel methodological approach that examines the shape and variability of HGS(t) curves recorded from community-dwelling older adults. Functional principal component analysis (FPCA) was applied to assess the consistency of individual trials and the representativeness of mean curves. Statistical non-parametric mapping (SnPM) was then used to identify time regions showing significant differences between groups. Complementary analyses of discrete and derivative parameters, together with non-parametric comparisons based on the Hodges–Lehmann estimator and corresponding 95% confidence intervals, were conducted to quantify effect sizes. FPCA revealed high within-participant consistency, supporting the use of mean curves for group-level comparisons. SPM analyses indicated significant differences in the early force development phase. Importantly, this approach shows that sex differences are attributable to magnitude effects, with men generating higher forces and faster early rates of force development, and not to differences in the neuromuscular strategy of force production. Traditional discrete parameters partly captured these patterns but failed to reflect the full temporal dynamics. This methodological approach to the HGS curve may provide further insights into neuromuscular control mechanisms that cannot be truly captured by the minimalistic HGS discrete parameters. Full article

(This article belongs to the Section Biomechanics and Sports Medicine)

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24 pages, 1315 KB

Open AccessEditor’s ChoiceArticle

Algal and Cyanobacteria Cell Walls as Biosorbents for Phenolic Compounds: Comparative Performance and Sustainability Assessment of Limnospira platensis

by Lorenzo Mollo, Alessandra Norici, Linda Raffaelli and Alessia Amato

Bioengineering 2026, 13(4), 373; https://doi.org/10.3390/bioengineering13040373 - 24 Mar 2026

Viewed by 953

Abstract

Adsorption is a method widely used to remove low-molecular-weight organics from wastewaters, and phenolic compounds from olive mill wastewater are a persistent class of bioactive pollutants of environmental concern. We screened eleven microalgal candidates at 0.10 g·L⁻¹ using batch kinetics fitted with [...] Read more.

Adsorption is a method widely used to remove low-molecular-weight organics from wastewaters, and phenolic compounds from olive mill wastewater are a persistent class of bioactive pollutants of environmental concern. We screened eleven microalgal candidates at 0.10 g·L⁻¹ using batch kinetics fitted with the Lagergren pseudo-first-order model to obtain rate constants (k) and fitted equilibrium capacities (q_e). Cyanobacteria, particularly Anabaena spp. and Limnospira platensis, exhibited the highest adsorptive potential in the screening; wall-less species (e.g., Dunaliella salina, Isochrysis galbana) showed negligible surface adsorption, indicating that the presence and type of cell wall highly influence biosorption. L. platensis was selected for detailed study because of its established industrial cultivation and valorisation potential. Equilibrium experiments with HCl-functionalized L. platensis at four biomass loadings (0.10–1.00 g·L⁻¹; initial phenolic mix 30 mg·L⁻¹) showed that increasing dose reduced equilibrium concentration (C_e) but decreased specific uptake from ≈77 mg·g⁻¹ to ≈18 mg·g⁻¹ while removal rose from ~26% to ~61%. Nonlinear isotherm fitting favoured the Freundlich model (1/n < 1), consistent with heterogeneous, multi-site adsorption. Targeted macromolecular extractions abolished phenol uptake, demonstrating that the intact protein–polysaccharide matrix is essential for binding. L. platensis route delivered higher single-cycle removal (≈61%) compared to the maize-derived activated carbon reference (≈49%) while also incurring a 1.3-fold lower GWP (approximately 3 kg CO₂-eq per treatment) than the activated carbon route (approximately 4 kg CO₂-eq per treatment) in our model. Overall, L. platensis represents a lower-impact alternative for natural phenols remediation, especially when integrated into valorisation pathways that recover algal co-products. Full article

(This article belongs to the Special Issue Microalgae Biotechnology and Microbiology: Prospects and Applications)

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19 pages, 2500 KB

Open AccessEditor’s ChoiceArticle

Comparison of 2D, 3D In Vitro, and Ex Vivo Platforms for Modeling the Rat Small Intestine

by Shani Elias-Kirma, Reece McCoy, Douglas van Niekerk, Verena Stoeger, Sophie Oldroyd, Emma Sumner, Achilleas Savva and Róisín M. Owens

Bioengineering 2026, 13(3), 349; https://doi.org/10.3390/bioengineering13030349 - 17 Mar 2026

Viewed by 992

Abstract

Physiologically relevant in vitro intestinal models are essential for studying key physiological processes, including barrier function, drug screening and gut-microbiota interactions. However, conventional 2D culture systems often fail to recapitulate structural and functional complexity. Here, we aimed to validate a 3D bioelectronic transmembrane [...] Read more.

Physiologically relevant in vitro intestinal models are essential for studying key physiological processes, including barrier function, drug screening and gut-microbiota interactions. However, conventional 2D culture systems often fail to recapitulate structural and functional complexity. Here, we aimed to validate a 3D bioelectronic transmembrane platform, previously used for monitoring human intestinal epithelium and vascular endothelium, for modeling the rat small intestinal barrier in vitro. The device integrates a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) scaffold supporting co-cultures of rat intestinal epithelial cells (IEC-6) and rat fibroblasts (208F), enabling real-time monitoring of barrier formation through electrical measurements using electrochemical impedance spectroscopy (EIS). Barrier formation was monitored over 21 days and exhibited a time-dependent increase in barrier resistance. The 3D platform was compared with traditional 2D insert-based cultures and ex vivo rat tissue using an Ethylene Glycol Tetraacetic Acid (EGTA)-induced calcium switch assay to evaluate barrier disruption and recovery. EGTA treatment and removal induced reversible barrier disruption in the 3D in vitro and ex vivo models, whereas 2D in vitro cultures showed limited recovery. These findings demonstrate that the 3D platform more faithfully recapitulates native tissue architecture and function, closely paralleling ex vivo responses. Our study highlights the importance of validating advanced 3D in vitro models and establishes this bioelectronic platform as a robust tool for drug screening, barrier studies, and preclinical gastrointestinal research. Full article

(This article belongs to the Special Issue Advanced Physical Techniques in Tissue Engineering and Regenerative Medicine)

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14 pages, 11989 KB

Open AccessEditor’s ChoiceArticle

Detecting Condylar Lift-Off with a Piezoelectric Smart Knee Replacement

by Brandon D. Hines, Ryan Willing and Steven R. Anton

Bioengineering 2026, 13(3), 346; https://doi.org/10.3390/bioengineering13030346 - 17 Mar 2026

Viewed by 663

Abstract

Smart knee replacement technology seeks to provide an in vivo method of tracking long-term postoperative joint loads with the goal of identifying clinically relevant phenomena linked to postoperative dissatisfaction in real time. This study evaluated the ability of a piezoelectric compartmental force and [...] Read more.

Smart knee replacement technology seeks to provide an in vivo method of tracking long-term postoperative joint loads with the goal of identifying clinically relevant phenomena linked to postoperative dissatisfaction in real time. This study evaluated the ability of a piezoelectric compartmental force and compartmental center of pressure sensing total knee replacement to sense condylar lift-off, which is a clinically relevant phenomenon commonly attributed to postoperative dissatisfaction. A commercially available total knee replacement was modified to include six piezoelectric transducers capable of measuring compartmental forces and tibiofemoral centers of pressure on the articular surface of the tibial bearing insert. The smart knee replacement was evaluated with a six-degree-of-freedom joint motion simulator applying a varus lift-off profile. The study demonstrated that the lift-off was evident in both the sensed joint loads and the localized tibiofemoral centers of pressure obtained from the piezoelectric sensing system. The results indicated that the piezoelectric smart knee replacement could be effective for detecting this clinically problematic mechanical issue. Full article

(This article belongs to the Special Issue Joint Biomechanics and Implant Design)

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20 pages, 2068 KB

Open AccessEditor’s ChoiceArticle

Establishment of a 3D Multicellular HCC Tumor Spheroid Model to Unravel Nrf2’s Influence on the Tumor Immune Microenvironment

by Nicole Böttcher, Philipp Krumm, Rosanna Huchzermeier, Lara Berschkeit, Johanna Vollmer, Julie Dick, Thomas Pufe and Athanassios Fragoulis

Bioengineering 2026, 13(3), 336; https://doi.org/10.3390/bioengineering13030336 - 13 Mar 2026

Viewed by 2226

Abstract

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related death, yet adequate in vitro models mimicking the tumor immune microenvironment (TIME) are rare. Specifically, the role of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in modulating interactions between tumor cells [...] Read more.

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related death, yet adequate in vitro models mimicking the tumor immune microenvironment (TIME) are rare. Specifically, the role of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in modulating interactions between tumor cells and tumor-associated macrophages (TAMs) is not fully understood. We established a 3D multicellular tumor spheroid (MCT) model using murine N-HCC25 cells with CRISPR/Cas9-mediated knockouts of Nrf2 and its negative regulator Kelch-like ECH-associated protein 1 (Keap1), the latter mimicking constitutive activation. N-HCC25 cells were co-cultured with bone marrow-derived macrophages (BMDMs) isolated from wild-type and Nrf2-knockout C57BL/6J mice. We compared co-culture setups (conditioned media, transwell systems, direct contact) using RT-qPCR, flow cytometry, and invasion assays. 3D spheroid systems better preserved stemness than 2D cultures and revealed functional Nrf2-dependent effects such as increased Vegf-α secretion in Keap1-deficient spheroids. Among the different co-cultivation models, the most profound effects were observed in the MCT model. Macrophages successfully integrated into the spheroids and triggered invasive outgrowth, whereas MCTs containing Nrf2-deficient macrophages displayed markedly reduced tumor spheroid growth and lower programmed cell death ligand-1 expression. These findings demonstrate that Nrf2 signaling in macrophages fosters an immunosuppressive and pro-invasive microenvironment. The established MCT model provides a suitable platform to further unravel Nrf2-dependent mechanisms in the HCC TIME. Full article

(This article belongs to the Special Issue 3D Cell Culture Systems: Current Technologies and Applications)

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18 pages, 2193 KB

Open AccessEditor’s ChoiceArticle

Impact of Ball-Milling and Thermal Hydrolysis on Physicochemical Properties and Anaerobic Digestion Kinetics of Mixed Slaughterhouse and Agricultural Wastes

by Sang Heon Lee, Oh Hyun Gweon, Hye Sun Lee, Byoung Seung Jeon, Youngwook Go, Chang Sook Jin, Youngseob Yu, Byoung-In Sang and Jin Hyung Lee

Bioengineering 2026, 13(3), 326; https://doi.org/10.3390/bioengineering13030326 - 11 Mar 2026

Viewed by 1008

Abstract

Slaughterhouse by-products are promising feedstocks for anaerobic digestion due to their high lipid and protein content. However, their complex structures often limit hydrolysis, and excessive pretreatment can induce inhibitory conditions. This study evaluates the effects of ball-milling (BM), ball-milling with water (BM + [...] Read more.

Slaughterhouse by-products are promising feedstocks for anaerobic digestion due to their high lipid and protein content. However, their complex structures often limit hydrolysis, and excessive pretreatment can induce inhibitory conditions. This study evaluates the effects of ball-milling (BM), ball-milling with water (BM + water), and combined thermal hydrolysis and ball-milling (THP + BM) on the digestion performance of a mixed substrate of slaughterhouse and agricultural wastes. The results demonstrate that all BM-based pretreatments significantly improved digestion kinetics, reducing the lag phase by 26–66% and shortening the T₅₀ values by approximately 40% compared to the untreated substrate. While no statistically significant differences were observed in the ultimate methane yield, the onset of methanogenesis was markedly accelerated in the BM and BM + water treatments. In contrast, despite achieving superior solubilization, the THP + BM treatment failed to provide proportional kinetic enhancements. This was attributed to a severe initial metabolic imbalance—characterized by a pH drop below the inhibitory threshold (6.33)—which induced physiological stress and delayed the functional recovery of methanogens. These findings indicate that while ball-milling effectively facilitates digestion initiation by enhancing physical accessibility, the intensity of combined thermal-mechanical processes must be strategically optimized. For high-strength organic biomass, managing pretreatment severity is crucial to prevent initial acid stress and maximize process efficiency. Full article

(This article belongs to the Special Issue Anaerobic Digestion Advances in Biomass and Waste Treatment)

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21 pages, 3598 KB

Open AccessEditor’s ChoiceArticle

Breeding Chlorophyll-Deficient Mutants of Chlorella vulgaris to Enhance Consumer Acceptance

by Malene Lihme Olsen, Daniel Poveda-Huertes, Duygu Ozcelik, Emil Gundersen, Jens Frederik Bang Thøfner, Maryna Kobylynska, Stefania Marcotti, Roland A. Fleck, Damien McGrouther, Johan Andersen-Ranberg, Charlotte Jacobsen and Poul Erik Jensen

Bioengineering 2026, 13(3), 318; https://doi.org/10.3390/bioengineering13030318 - 10 Mar 2026

Viewed by 1647

Abstract

The use of microalgae as a food source is limited by consumers’ dislike of their organoleptic traits, primarily the intense green color and bitter taste associated with high chlorophyll content. The eukaryotic microalgae Chlorella vulgaris can grow under heterotrophic conditions, providing the opportunity [...] Read more.

The use of microalgae as a food source is limited by consumers’ dislike of their organoleptic traits, primarily the intense green color and bitter taste associated with high chlorophyll content. The eukaryotic microalgae Chlorella vulgaris can grow under heterotrophic conditions, providing the opportunity to cultivate chlorophyll-less strains. In this work we applied random mutagenesis for breeding chlorophyll-deficient C. vulgaris strains. Wild-type strain was UVC-radiated, and 12 colonies with changed pigmentation were selected. Based on phenotypic stability two mutants, M6 and M11, were selected for characterization of growth, pigment and biomass accumulation. Cultivation under photo-, mixo- and heterotrophic conditions revealed distinct phenotypes for the two mutants. M6 remained chlorophyll-deficient in all cultivation conditions tested, while chlorophyll was observed in M11 when grown under light. Under heterotrophic and mixotrophic growth conditions, both mutants were chlorophyll-deficient while biomass productivity, protein content, and amino acid composition remained similar to wild type. Characterization of the cellular ultrastructure of the wild type and mutants using cryo Focused Ion-Beam Scanning Electron Microscopy revealed that functional chloroplasts and thylakoid membranes were absent in the mutants. Our work demonstrates how a simple approach using UV mutagenesis and visual screening can provide novel strains of C. vulgaris with traits for improved consumer acceptance, without compromising the use of the algae biomass as a protein-rich food source. Full article

(This article belongs to the Special Issue Blue Economy: Innovative Strategies for Valorising Micro- and Macroalgae)

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35 pages, 10613 KB

Open AccessEditor’s ChoiceSystematic Review

Current Trends in Artificial Intelligence for Recognizing Work Postures to Prevent Work-Related Musculoskeletal Disorders: Systematic Review and Meta-Analysis by Occupational Activity

by Philippe Gorce and Julien Jacquier-Bret

Bioengineering 2026, 13(3), 298; https://doi.org/10.3390/bioengineering13030298 - 3 Mar 2026

Cited by 3 | Viewed by 2178

Abstract

The use of artificial intelligence (AI) to recognize postures is a promising approach for the prevention of work-related musculoskeletal disorders (WMSDs). The aim was to conduct a systematic review with meta-analysis to assess the performance of work posture recognition systems during occupational activity. [...] Read more.

The use of artificial intelligence (AI) to recognize postures is a promising approach for the prevention of work-related musculoskeletal disorders (WMSDs). The aim was to conduct a systematic review with meta-analysis to assess the performance of work posture recognition systems during occupational activity. The results were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Google Scholar, IEEE Xplore, PubMed/MedLine, and ScienceDirect databases were screened without date restrictions. Two authors independently selected articles and extracted data. Studies were included if they presented a performance analysis of an AI deep learning (DL) or machine learning (ML) method that assessed the WMSD risk associated with working postures. Only peer-reviewed studies written in English including accuracy, precision, specificity, sensitivity, or F1-score values were included. The risk of bias was assessed using the Prediction Model Study Risk of Bias Assessment Tool. Of the 157 unique records, 58 studies were selected. The five performance parameters were investigated and averaged for seven occupational activities, eight posture categories, and the AI methods (ML vs. DL). Statistical analyses showed that DL methods produced better results. The reported systems detected sitting and standing postures with high accuracy. The solutions proposed in Manufacturing and Construction were the most numerous and the most effective on average. The major limitation lies in the wide variety of methods used. This analysis is a valuable source of information for designing new detection systems that are effective, ergonomic, easy to use, and acceptable so that humans remain at the center of the production process as defined by Industry 5.0. Full article

(This article belongs to the Special Issue New Trends in Biomechanical Modeling in Musculoskeletal Disorders and Diseases)

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12 pages, 443 KB

Open AccessEditor’s ChoiceArticle

A Predictive Bioengineering Model of Dental Implant Instability in Systemic Bone Disorders: A Periotest-Based Analysis

by Liliana Sachelarie, Ramona Feier, Corina-Laura Ștefănescu, Mircea Grigorian, Rodica-Maria Murineanu, Zaharia Agripina and Loredana Liliana Hurjui

Bioengineering 2026, 13(3), 297; https://doi.org/10.3390/bioengineering13030297 - 3 Mar 2026

Cited by 1 | Viewed by 1035

Abstract

(1) Background: Dental implant instability represents a dynamic biomechanical process influenced by functional loading, peri-implant bone stiffness, and systemic conditions affecting bone metabolism. In patients with systemic bone disorders, altered material properties and impaired remodeling may reduce effective implant–bone interface stiffness, potentially increasing [...] Read more.

(1) Background: Dental implant instability represents a dynamic biomechanical process influenced by functional loading, peri-implant bone stiffness, and systemic conditions affecting bone metabolism. In patients with systemic bone disorders, altered material properties and impaired remodeling may reduce effective implant–bone interface stiffness, potentially increasing micromotion beyond what is detectable by conventional clinical indicators. The aim of this study was to develop and evaluate a predictive bioengineering model of implant instability based on Periotest-derived dynamic measurements. (2) Methods: A retrospective analysis was performed on 79 dental implants placed in patients with and without systemic bone disorders. Implant micromotion was quantified using Periotest values (PTVs). Linear and logistic regression analyses were applied to model the relationship between systemic bone status, implant location, and biomechanical instability (defined as PTV > +2.0). A load–stiffness–micromotion framework was used to provide mechanical interpretation of the findings. (3) Results: Implants placed in patients with systemic bone disorders exhibited significantly higher Periotest values compared to controls (+2.1 ± 1.3 vs. −0.4 ± 1.1; mean difference 2.5 PTV units, 95% CI 1.97–3.04; p < 0.001). High-risk biomechanical instability (PTV > +2.0) was observed in 46% of implants in the systemic group compared to 9% in controls. Multivariable logistic regression demonstrated that systemic bone disorders were independently associated with a 2.6-fold increase in the odds of high-risk instability after adjustment for implant location. The observed instability pattern was consistent with reduced effective peri-implant stiffness in systemically compromised bone. (4) Conclusions: Dental implant instability in systemically compromised patients can be interpreted as a load–stiffness imbalance at the implant–bone interface. The proposed predictive bioengineering framework links dynamic Periotest measurements with mechanical modeling and systemic bone status, enabling quantitative risk stratification beyond static stability assessments. Full article

(This article belongs to the Special Issue Mechanobiology in Biomedical Engineering—2nd Edition)

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45 pages, 8058 KB

Open AccessEditor’s ChoiceReview

Bioengineered 3D Human Trabecular Meshwork Models for Outflow Physiology and Glaucoma Research

by Andrea Valarezo, Pujhitha Ramesh, Rong Du, Rohit Sharma, Evan Davis, Susan T. Sharfstein, John Danias, Yiqin Du and Yubing Xie

Bioengineering 2026, 13(3), 291; https://doi.org/10.3390/bioengineering13030291 - 28 Feb 2026

Viewed by 2013

Abstract

Primary open angle glaucoma (POAG) is one of the leading causes of irreversible blindness and is associated with dysfunction of the trabecular meshwork (TM), a three-dimensional (3D) structure that regulates aqueous humor outflow and, consequently, intraocular pressure (IOP). IOP is the only modifiable [...] Read more.

Primary open angle glaucoma (POAG) is one of the leading causes of irreversible blindness and is associated with dysfunction of the trabecular meshwork (TM), a three-dimensional (3D) structure that regulates aqueous humor outflow and, consequently, intraocular pressure (IOP). IOP is the only modifiable factor for glaucoma. Outflow facility is the inverse of aqueous humor outflow resistance caused by the presence of the TM and adjacent tissues, and reflects the TM’s central role in IOP control, representing the most physiologically relevant measure of human trabecular meshwork (HTM) function. Therefore, development of ex vivo systems to study outflow facility and IOP regulation is critical for advancing glaucoma research. We present a comprehensive review of bioengineering approaches to generation of 3D HTM models using synthetic, natural, and hybrid hydrogels, micro- and nanofabricated synthetic substrates or porous scaffolds, and microfluidic devices. These 3D HTM systems have been designed to capture key features such as topography, stiffness, and fluid flow in the conventional outflow pathway. In particular, we highlight HTM models that recapitulate IOP regulation and allow measurement of outflow facility, which directly reflect pressure-dependent outflow resistance in dynamic HTM physiology and glaucoma pathophysiology. By integrating these bioengineering approaches with emerging stem cell technologies, this review offers an evidence-based landscape overview and framework for designing next-generation 3D human-relevant TM models for outflow physiological studies and IOP-modulating drug discovery. Full article

(This article belongs to the Special Issue Bioengineering and the Eye—3rd Edition)

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18 pages, 1379 KB

Open AccessEditor’s ChoiceReview

Bioresorbable Vascular Stents: How Neutrophil Extracellular Traps Influence Biocompatibility, Degradation Kinetics, and Device Performance

by Rasit Dinc and Nurittin Ardic

Bioengineering 2026, 13(3), 278; https://doi.org/10.3390/bioengineering13030278 - 27 Feb 2026

Cited by 4 | Viewed by 1329

Abstract

Bioresorbable scaffolds (BRS; also referred to as bioresorbable vascular scaffolds, BVS) represent a promising approach in interventional cardiology, offering theoretical advantages such as temporary mechanical support followed by complete resorption. However, clinical experience has revealed challenges, including late-stage scaffold thrombosis and heterogeneous scaffold [...] Read more.

Bioresorbable scaffolds (BRS; also referred to as bioresorbable vascular scaffolds, BVS) represent a promising approach in interventional cardiology, offering theoretical advantages such as temporary mechanical support followed by complete resorption. However, clinical experience has revealed challenges, including late-stage scaffold thrombosis and heterogeneous scaffold discontinuity during degradation, prompting investigation into host immune responses. Neutrophil extracellular traps (NETs), which are network-like structures composed of decondensed chromatin decorated with antimicrobial proteins, have emerged as critical mediators of vascular inflammation and thrombosis. This review explores the intersection between NET biology and BRS performance, investigating how NETosis affects biocompatibility, degradation kinetics, and device-related complications. We discuss the molecular mechanisms that trigger neutrophil activation and NET formation in scaffold materials, the effect of NET components on polymeric and metallic scaffold degradation, and emerging biomarkers to monitor NET-mediated complications. We also evaluate therapeutic strategies targeting NET pathways, including DNase-based therapies, peptidylarginine deiminase 4 (PAD4) inhibitors, and anti-inflammatory coatings that can optimize next-generation BRS outcomes. Understanding the immunological environment surrounding bioresorbable vascular devices is crucial for developing scaffolds that deliver predictable degradation while minimizing adverse inflammatory responses. Full article

(This article belongs to the Section Biomedical Engineering and Biomaterials)

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17 pages, 870 KB

Open AccessEditor’s ChoiceArticle

Control of Joint Reaction Forces During Single-Joint Strengthening Exercises via Adaptive Electromechanical Technologies: An Analytical Biomechanical Framework

by Andrea Biscarini

Bioengineering 2026, 13(3), 270; https://doi.org/10.3390/bioengineering13030270 - 26 Feb 2026

Viewed by 1396

Abstract

Background: Modern electromechanical technologies can be integrated into strength training machines to regulate the magnitude, direction, and point of application of resistance during exercise, either through preprogrammed settings or adaptively in response to real-time kinematic data. However, this potential remains largely unexplored. [...] Read more.

Background: Modern electromechanical technologies can be integrated into strength training machines to regulate the magnitude, direction, and point of application of resistance during exercise, either through preprogrammed settings or adaptively in response to real-time kinematic data. However, this potential remains largely unexplored. The objective of this study was to investigate how these new-generation devices may be managed to enable precise control of the mechanical load applied to specific joint structures during strengthening exercises. Methods: A foundational framework of biomechanical equations was developed to establish the functional relationships between joint reaction forces and key variables, including kinematic parameters (joint angle, angular velocity, and angular acceleration) and resistance characteristics (magnitude, direction, and point of application). The analysis focused on analytically determined single-joint exercises, which are commonly employed in early-stage rehabilitation and athletic conditioning programs. Results: Application of the model to single-joint knee extension exercises demonstrated that the anterior cruciate ligament (ACL)-loading shear tibiofemoral force can be entirely eliminated throughout the full range of knee motion, without increasing either the tibiofemoral compressive force or the posterior cruciate ligament (PCL)-loading shear component, while preserving the desired peak and profile of the resistance torque. Conclusion: The proposed analytical framework enables a comprehensive understanding of how to regulate resistance parameters through advanced electromechanical technologies to minimize joint stress during single-joint strengthening exercises. Precise control of joint reaction forces during exercise is critical for the design of therapeutic and safety-enhanced training protocols. Full article

(This article belongs to the Special Issue Biomechanics of Physical Exercise)

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13 pages, 1472 KB

Open AccessEditor’s ChoiceArticle

Preliminary Effects of Hyperbaric Oxygen Therapy on Hair Follicle Characteristics in Healthy Subjects

by Hee Young Lee, Ji Yong Lee, Seung Chan Kim and Yoonsuk Lee

Bioengineering 2026, 13(2), 240; https://doi.org/10.3390/bioengineering13020240 - 19 Feb 2026

Viewed by 1873

Abstract

Background: Hyperbaric oxygen therapy (HBOT) has regenerative effects in various tissues, but its impact on hair follicles is unclear. This preliminary study evaluated HBOT-induced changes in hair and scalp characteristics in healthy adults. Methods: Nine healthy volunteers completed 50 HBOT sessions [...] Read more.

Background: Hyperbaric oxygen therapy (HBOT) has regenerative effects in various tissues, but its impact on hair follicles is unclear. This preliminary study evaluated HBOT-induced changes in hair and scalp characteristics in healthy adults. Methods: Nine healthy volunteers completed 50 HBOT sessions over three months (2.0 ATA, 100% oxygen, 90 min per session). Objective assessments included follicle density, hairs per follicle, hair volume, and shaft thickness using the Becon phototrichogram system. Subjective evaluations were conducted via a 7-point Likert questionnaire on scalp appearance, hair density, thickness, growth, and shedding. Pre- and post-treatment data were compared using paired statistical tests. Results: Positive trends were observed in follicle density (61.3→66.8 counts/cm²), hairs per follicle (1.24→1.33), and hair volume (24.9→27.7%), though not statistically significant. Hair shaft thickness decreased significantly (0.18→0.10 mm, p = 0.011), consistent with early anagen-phase regrowth. Subjective assessments showed significant improvements across all domains (p < 0.05). Scalp imaging visually supported these findings. Conclusions: HBOT may enhance hair follicle activation and scalp health in healthy adults. These preliminary findings justify further controlled studies to explore HBOT as a non-pharmacological approach to hair regeneration. Full article

(This article belongs to the Special Issue Advanced Physical Techniques in Tissue Engineering and Regenerative Medicine)

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20 pages, 3322 KB

Open AccessEditor’s ChoiceArticle

Parametric Finite Element Evaluation of Load Redistribution Under Progressive Lumbar Disc Degeneration

by Oleg Ardatov, Sofia Rita Fernandes, Artūras Kilikevičius and Vidmantas Alekna

Bioengineering 2026, 13(2), 234; https://doi.org/10.3390/bioengineering13020234 - 17 Feb 2026

Cited by 2 | Viewed by 1478

Abstract

This study presents a finite element (FE) investigation of intervertebral disc (IVD) degeneration in the human lumbar spine (L1–L3 segment). The model, based on CT-derived geometry and isotropic hyperelastic representation of disc tissues, incorporates controlled simplifications, detailed in the limitations section. Degenerative changes [...] Read more.

This study presents a finite element (FE) investigation of intervertebral disc (IVD) degeneration in the human lumbar spine (L1–L3 segment). The model, based on CT-derived geometry and isotropic hyperelastic representation of disc tissues, incorporates controlled simplifications, detailed in the limitations section. Degenerative changes were parametrically simulated across healthy, mild, moderate, and severe stages by reducing disc height (up to 60%), nucleus pulposus volume (up to 70%), and adjusting tissue stiffness to reflect dehydration and fibrosis. Displacement-controlled compressive loading was applied to assess von Mises stress distributions, reaction forces, and load transfer mechanisms. Results indicate significant load redistribution: annulus fibrosus stresses increased by up to 175% in severe degeneration, while nucleus pulposus stresses decreased by ~70%, indicating a diminished compressive load-bearing contribution of the nucleus. Model predictions were validated against cadaveric and in vivo data, confirming trends in intradiscal pressure (IDP) reductions (40–70%) and stress elevations. The parametric framework elucidates interactions between geometric and material changes, providing clinicians with insights into degeneration progression and guiding biomedical engineers in implant design and interventions. Full article

(This article belongs to the Special Issue Spine Biomechanics)

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19 pages, 6361 KB

Open AccessEditor’s ChoiceArticle

Increased Cervical Disc Height and Decreased Neck Pain and Disability Following Improvement in Cervical Lordosis and Posture Using Chiropractic BioPhysics

by Evan A. Katz, Seana B. Katz, Sophie F. Katz, Curtis A. Fedorchuk, Cole G. Fedorchuk and Douglas F. Lightstone

Bioengineering 2026, 13(2), 229; https://doi.org/10.3390/bioengineering13020229 - 15 Feb 2026

Cited by 1 | Viewed by 3691

Abstract

Background/Objectives: Cervical degenerative disc disease (DDD) is associated with decreased disc height, spinal arthrosis, decreased spinal stability, neck pain (NP), and increased years living with disability and global disease burden. Methods: A total of 64 patients (19 males, 45 females) between 23 and [...] Read more.

Background/Objectives: Cervical degenerative disc disease (DDD) is associated with decreased disc height, spinal arthrosis, decreased spinal stability, neck pain (NP), and increased years living with disability and global disease burden. Methods: A total of 64 patients (19 males, 45 females) between 23 and 77 years (mean age of 49.05 ± 3.34 years) presented to a private practice with NP and disability. Pre-treatment radiographs revealed decreased cervical curvature (ARA C2–C7) measuring −6.18 ± 3.06° (ideal is −42.0°), anterior head translation (Tz C2–C7) measuring 22.03 ± 2.39 mm (ideal is 0 mm), anterior cervical disc height (ADH C2–C7) measuring 3.68 ± 0.20 mm, and posterior cervical disc height (PDH C2–C7) measuring 3.21 ± 0.15 mm. Pre-treatment NP numeric rating scale (NRS) scored 6.66 ± 0.27, and neck disability index (NDI) scored 40.28 ± 1.42%, indicating moderate disability due to NP. Patients were treated using Chiropractic BioPhysics^® (CBP^®) Mirror Image^® spinal rehabilitation for mean values of 37.80 ± 2.44 treatment visits over 19.48 ± 3.89 weeks at a frequency of 2.89 ± 0.45 treatment visits per week. Results: Post-treatment radiographs revealed improvements in ARA C2–C7 to −19.95 ± 3.05°, Tz C2–C7 to 12.11 ± 2.34 mm, ADH C2-C7 to 5.19 ± 0.21 mm, and PDH C2-C7 to 4.36 ± 0.16 mm. Post-treatment patient-reported outcomes showed improvements in NP NRS to 1.52 ± 0.26 and NDI to 12.66 ± 0.96, indicating minimal NP and disability. Conclusions: CBP^® helps improve sagittal cervical spinal alignment and posture, which may help improve cervical disc height and NP and disability in adult patients with cervical DDD. Full article

(This article belongs to the Section Biomechanics and Sports Medicine)

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33 pages, 2135 KB

Open AccessEditor’s ChoiceReview

The Osteoimmunologic Basis of Biologic and Bioengineered Scaffolds in Fracture Healing

by Hannah Shelby, Sarah Bergren, Julian Wier, Edward M. Schwarz and Jay R. Lieberman

Bioengineering 2026, 13(2), 223; https://doi.org/10.3390/bioengineering13020223 - 14 Feb 2026

Cited by 4 | Viewed by 1099

Abstract

Fracture nonunion or delayed union remains a significant clinical problem that burdens both the patient and the healthcare system. Defined as failure for bone to unite 9 months post injury or 3 months with no progression toward union, the pathology of nonunion may [...] Read more.

Fracture nonunion or delayed union remains a significant clinical problem that burdens both the patient and the healthcare system. Defined as failure for bone to unite 9 months post injury or 3 months with no progression toward union, the pathology of nonunion may require multiple surgical interventions with associated morbidity. Increasing evidence has highlighted that nonunion is a multifaceted problem, not only a result of mechanical failure, but also a product of persistent dysregulation of the osteoimmune microenvironment manifested as impaired osteogenesis and bone healing. While current approaches focus on enhanced fixation and various bone grafting strategies, these treatments often fail to coordinate healing with osteoimmune regulation. This review summarizes the emerging biologic and bioengineering approaches that target osteoimmunology to enhance fracture repair. Scaffold systems, including metals, bioceramics, hydrogels, and micro/nanoparticle formulations, are being increasingly engineered to provide structural support while directing macrophage polarization and stimulating osteogenic signaling. We also review cell-based therapies and gene-modified constructs that are being developed to introduce osteoimmunology cues that halt chronic inflammation and promote an osteogenic microenvironment. Full article

(This article belongs to the Special Issue Application of Bioengineering to Orthopedics)

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17 pages, 4590 KB

Open AccessEditor’s ChoiceArticle

Beyond Decellularization: Remnant Mitochondrial DNA Can Act as Hidden Damage-Associated Molecular Pattern

by Elena V. A. van Hengel, Kuan Liu, Henk P. Roest, Jorke Willemse, Kimberley Ober-Vliegen, Selina M. W. Teurlings, Jeroen de Jonge, Monique M. A. Verstegen and Luc J. W. van der Laan

Bioengineering 2026, 13(2), 193; https://doi.org/10.3390/bioengineering13020193 - 9 Feb 2026

Cited by 1 | Viewed by 1397

Abstract

Tissue decellularization aims to obtain bioscaffolds for regenerative applications by removing all cellular components while preserving the extracellular matrix (ECM) architecture. Although decellularization removes the majority of linear nuclear DNA (nDNA), residual amounts remain detectable. However, the fate of circular mitochondrial DNA (mtDNA) [...] Read more.

Tissue decellularization aims to obtain bioscaffolds for regenerative applications by removing all cellular components while preserving the extracellular matrix (ECM) architecture. Although decellularization removes the majority of linear nuclear DNA (nDNA), residual amounts remain detectable. However, the fate of circular mitochondrial DNA (mtDNA) after decellularization has not yet been reported. Cell death or injury can cause the release of mtDNA, which is resistant to breakdown by exonucleases. Extracellular mtDNA acts as a damage-associated molecular pattern (DAMP) that can trigger immune responses. The aim of this study is to assess the presence of residual mtDNA in the liver, bile duct, and vascular scaffolds after decellularization and whether this causes inflammatory responses in macrophages. Decellularized tissues showed a marked reduction in total DNA content well below the threshold of 50 ng/mg tissue. However, in liver and vascular scaffolds, a relative increase in the mtDNA:nDNA ratio was detected in the remnant DNA fraction. Residual mtDNA in bioscaffolds acted as DAMPs causing macrophage activation, as shown by increased cell proliferation and cytokine production. Strategies to further reduce remnant mtDNA were tested. We found that treatment with the endonuclease enzyme HpaII was effective in degrading residual mtDNA. Importantly, mtDNA removal resulted in a significantly reduced macrophage activation. In conclusion, our study shows that mtDNA is relatively resistant to the decellularization procedure and can act as a DAMP in bioscaffolds. This underscores the importance of removing mtDNA from decellularized bioscaffolds to improve the immunocompatibility for biomedical applications. Full article

(This article belongs to the Special Issue Extracellular Matrix Biomaterial for Tissue Engineering and Regenerative Medicine, 2nd Edition)

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13 pages, 2395 KB

Open AccessEditor’s ChoiceArticle

Engineering the Future of Heart Failure Therapeutics: Integrating 3D Printing, Silicone Molding, and Translational Development for Implantable Cardiac Devices

by Carleigh Eagle, Aarti Desai, Michael Franklin, Robert Pooley, Elizabeth Johnson, Shawn Robinson, Mark Lopez and Rohan Goswami

Bioengineering 2026, 13(2), 192; https://doi.org/10.3390/bioengineering13020192 - 8 Feb 2026

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Abstract

Three-dimensional (3D) anatomic modeling derived from high-resolution medical imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI), has been increasingly adopted in preclinical testing and device development. This white paper describes a cardiac-specific workflow that integrates 3D printing and silicone molding [...] Read more.

Three-dimensional (3D) anatomic modeling derived from high-resolution medical imaging, such as computed tomography (CT) and magnetic resonance imaging (MRI), has been increasingly adopted in preclinical testing and device development. This white paper describes a cardiac-specific workflow that integrates 3D printing and silicone molding for support device development and procedural simulation. Patient-derived computed tomography angiography data were segmented using FDA-cleared medical modeling software to isolate the left ventricular anatomy and were further processed in computer-aided design (CAD) to ensure accurate physiological wall thickness and structural fidelity. Material jetting 3D printing was performed on a Stratasys J750 using material distributions designed to mimic the mechanical properties of myocardium, thereby approximating myocardial compliance. In parallel, stereolithography apparatus molds were designed from the left ventricle CAD model to cast transparent, pliable left ventricular models in Sorta-Clear™ 18 silicone. The 3D-printed models preserved intricate morphological detail and were suitable for mechanical manipulation and device deployment studies, whereas silicone models offered tunable mechanical properties, transparency for visualization, and durability for repeated use. Together, these complementary modalities provided rapid manufacturing capability and application-relevant physical representation. Case-specific parameters, strengths, and limitations of both models in enhancing patient care and device testing are highlighted, with relevance to heart failure applications. Current knowledge gaps, workflow and integration challenges, and future opportunities are identified, positioning this work as a reference framework for continued innovation in anatomic modeling. Within the collaborative framework of Mayo Clinic’s Anatomic Modeling Unit and Simulation Center, this integrated modeling workflow demonstrates the value of multidisciplinary collaboration between engineers and clinicians. Clinically, these patient-specific left ventricular models may enable pre-procedural device sizing and positioning and may support simulation of mechanical circulatory support (MCS) deployment while identifying possible anatomic constraints prior to intervention. This workflow has direct applicability in advanced heart failure patients undergoing MCS support, such as the Impella axillary MCS device or the durable LVAD, with potential to reduce procedural uncertainty while reducing complications and improving peri-procedural outcomes. Additionally, these models also serve as high-accuracy educational tools, enabling trainees and multidisciplinary care teams to visualize and possibly rehearse procedural steps while gaining hands-on experience in a risk-free environment. Full article

(This article belongs to the Special Issue Advancements in Biocompatible Materials for Implantable Medical Devices)

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25 pages, 515 KB

Open AccessEditor’s ChoiceArticle

Engineering Elite Swimming Start Performance: Key Kinetic and Kinematic Variables with Reference Values

by Dennis-Peter Born, Lina Nussbaumer, Markus Buck, Jesús J. Ruiz-Navarro and Michael Romann

Bioengineering 2026, 13(2), 180; https://doi.org/10.3390/bioengineering13020180 - 3 Feb 2026

Cited by 1 | Viewed by 1928

Abstract

To provide deeper insights into the complex and multidimensional nature of swimming start performance, the present study aimed to determine its key performance indicators (KPIs) and provide percentile-based reference values for elite junior and adult swimmers. Hence, routine performance analysis data of Swiss [...] Read more.

To provide deeper insights into the complex and multidimensional nature of swimming start performance, the present study aimed to determine its key performance indicators (KPIs) and provide percentile-based reference values for elite junior and adult swimmers. Hence, routine performance analysis data of Swiss junior and senior national team members were analyzed, including multiple European champions, World champions, Olympic medalists and a World record holder (n = 136, age: 18.3 ± 3.6 [13–32] years, World Aquatics swimming points: 761 ± 73 [609–1061]). All kinetic and kinematic variables measured by the instrumented starting block were analyzed, and variables with pairwise correlation > 0.80 were clustered using principal component analysis with orthogonal Varimax rotation, retaining components with Eigenvalue > 1.0 and factor loadings > 0.6. The highest loaded variables of each component were used as independent variables, alongside the variables with low co-variance, to determine KPIs with multiple linear regression analysis. As such, peak and average power (p ≤ 0.05), front horizontal and total vertical peak forces (p ≤ 0.04), timing of peak power and rear horizontal forces (p ≤ 0.02), resultant grab forces and their timing (p ≤ 0.05), center-of-gravity height at take-off (p = 0.03), take-off horizontal and vertical velocity (p = 0.02), resultant entry velocity (p = 0.01), entry time (p < 0.01), distance before the first kick (p < 0.01), maximal swimming depth (p = 0.02) and distance before breaking through the water surface (p < 0.01) showed a significant effect on the dependent variables (15 m start time). In conclusion, swimmers should maximize power and force production peaking earlier and grab forces peaking later during the block phase. They should increase take-off and entry velocities, distance before the first undulating kick, maximal swimming depth and underwater distance. Full article

(This article belongs to the Special Issue Biomechanics of Physical Exercise)

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22 pages, 1871 KB

Open AccessEditor’s ChoiceSystematic Review

High-Intensity Laser Therapy Versus Extracorporeal Shockwave Therapy for Lateral Elbow Tendinopathy: A Systematic Review and Meta-Analysis

by Pei-Ching Wu, Dung-Huan Liu, Yang-Shao Cheng, Chih-Sheng Lin and Fu-An Yang

Bioengineering 2026, 13(2), 155; https://doi.org/10.3390/bioengineering13020155 - 28 Jan 2026

Cited by 1 | Viewed by 2249

Abstract

Purpose: In this systematic review, we compare the effectiveness of high-intensity laser therapy (HILT) and extracorporeal shockwave therapy (ESWT) in treating lateral elbow tendinopathy (LET). Methods: A comprehensive search of PubMed, the Cochrane Library, and EMBASE was conducted from database inception to 23 [...] Read more.

Purpose: In this systematic review, we compare the effectiveness of high-intensity laser therapy (HILT) and extracorporeal shockwave therapy (ESWT) in treating lateral elbow tendinopathy (LET). Methods: A comprehensive search of PubMed, the Cochrane Library, and EMBASE was conducted from database inception to 23 June 2025 to identify randomized controlled trials (RCTs) comparing the two interventions. The primary outcome was pain intensity (visual analog scale or numeric rating scale). Secondary outcomes included upper-limb disability (qDASH), grip strength (pain-free or maximal), ultrasound-measured common extensor tendon thickness, and safety (adverse events and withdrawals). Two reviewers independently extracted data and assessed methodological quality using the Physiotherapy Evidence Database (PEDro) scale; the certainty of evidence was rated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Effects were synthesized as SMD (95% CI) using random- or fixed-effects models based on heterogeneity (I²). Significance was set at p < 0.05. Results: Four RCTs met the inclusion criteria and 169 participants were included. Methodological quality was moderate, with moderate-quality evidence indicating a significant improvement in short-term and medium-term upper-limb function in favor of HILT (SMD = −0.42; 95% CI: −0.73 to −0.12 and SMD = −0.50; 95% CI: −0.94 to −0.06, respectively). Evidence ranging from low to moderate quality showed no significant differences between the HILT and ESWT groups in terms of short-term or medium-term resting pain (SMD = −0.50; 95% CI: −1.15 to 0.16 and SMD = −0.42; 95% CI: −1.06 to 0.22, respectively), short-term or medium-term activity pain (SMD = −0.38; 95% CI: −1.05 to 0.29 and SMD = −0.73; 95% CI: −1.65 to 0.19, respectively), short-term or medium-term grip strength (SMD = 0.24; 95% CI: −0.20 to 0.67 and SMD = 0.20; 95% CI: −0.16 to 0.55, respectively), or short-term or medium-term common extensor tendon thickness (SMD = 0.04; 95% CI: −0.50 to 0.59 and SMD = −0.00; 95% CI: −0.55 to 0.55, respectively). Conclusions: HILT appears to offer significant benefits in improving upper-limb function at short-term (<1 month) and medium-term (1–3 months) follow-up. Regarding pain, grip strength, and tendon thickness, the pooled effects did not show clear between-group differences. Evidence certainty ranged from low to moderate, demonstrating that trials with a follow-up period beyond 3 months are needed to evaluate long-term efficacy. Systematic review registration number: PROSPERO: CRD420251026387. Full article

(This article belongs to the Section Biomechanics and Sports Medicine)

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23 pages, 16175 KB

Open AccessEditor’s ChoiceArticle

The Effects of Ovine-Derived Reinforced Tissue Matrix Surrounding Silicone-Based Implants in a Rat Prepectoral Reconstruction Model

by Sai L. Pinni, Cameron Martin, Nicholas Fadell, Xiaochao Xia, Evan Marsh, Lauren Schellhardt, Xiaowei Li, Matthew D. Wood and Justin M. Sacks

Bioengineering 2026, 13(2), 150; https://doi.org/10.3390/bioengineering13020150 - 28 Jan 2026

Viewed by 1128

Abstract

Silicone-based implants have been widely used in breast reconstruction but have also been associated with poorly understood complications, including pathologic foreign body responses such as capsular contracture. In this study, we leveraged 3D-printing technology to generate silicone-based implants in a novel, anatomically relevant, [...] Read more.

Silicone-based implants have been widely used in breast reconstruction but have also been associated with poorly understood complications, including pathologic foreign body responses such as capsular contracture. In this study, we leveraged 3D-printing technology to generate silicone-based implants in a novel, anatomically relevant, prepectoral rat model. We used this model to evaluate the response to an extracellular matrix-based product: ovine-derived reinforced tissue matrix (RTM). Two-piece negative molds were developed through computer-aided design and 3D-printed. The molds were filled with various polydimethylsiloxane mixtures and dip-coated to fabricate implants. Implant material characterization revealed that the implants retained the original 3D-printed mold shape and qualitatively demonstrated a shell with an inner solid gel-like structure. Fabricated implants had smooth surfaces, as well as tunable features including implant stiffness (storage modulus). From initial studies in our rat model, placement of bilateral prepectoral implants allowed assessment of both muscle- and skin-facing capsules and were well-tolerated for at least 12 weeks. Comparison of the foreign body response between RTM-covered and uncovered (control) implants in this model revealed that the capsule thickness did not differ between groups at the 12-week endpoint. However, RTM reduced contractile fibroblasts (alpha-smooth muscle actin) and macrophages (Iba1) compared to the control. Our findings suggested that RTM may improve capsule quality by attenuating cells involved in fibrosis, even when total capsule thickness remains unchanged. However, these changes to cells involved in fibrosis were only observed at this early endpoint and may not predict long-term clinical outcomes. Full article

(This article belongs to the Section Biomedical Engineering and Biomaterials)

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