Bioengineering

2 pages, 143 KiB

Open AccessEditor’s ChoiceEditorial

by Carlo Albino Frigo

Bioengineering 2025, 12(2), 199; https://doi.org/10.3390/bioengineering12020199 - 18 Feb 2025

Viewed by 322

About fifty years ago, which seems very recent, new technologies for motion analysis were being developed, promising a more detailed and precise study of the human motor system [...] Full article

(This article belongs to the Special Issue Bioengineering of the Motor System)

13 pages, 480 KiB

Open AccessEditor’s ChoiceReview

Applications of Machine Learning-Driven Molecular Models for Advancing Ophthalmic Precision Medicine

by Rahul Kumar, Joshua Ong, Ethan Waisberg, Ryung Lee, Tuan Nguyen, Phani Paladugu, Maria Chiara Rivolta, Chirag Gowda, John Vincent Janin, Jeremy Saintyl, Dylan Amiri, Ansh Gosain and Ram Jagadeesan

Bioengineering 2025, 12(2), 156; https://doi.org/10.3390/bioengineering12020156 - 6 Feb 2025

Viewed by 1083

Abstract

Ophthalmic diseases such as glaucoma, age-related macular degeneration (ARMD), and optic neuritis involve complex molecular and cellular disruptions that challenge current diagnostic and therapeutic approaches. Advanced artificial intelligence (AI) and machine learning (ML) models offer a novel lens to analyze these diseases by [...] Read more.

Ophthalmic diseases such as glaucoma, age-related macular degeneration (ARMD), and optic neuritis involve complex molecular and cellular disruptions that challenge current diagnostic and therapeutic approaches. Advanced artificial intelligence (AI) and machine learning (ML) models offer a novel lens to analyze these diseases by integrating diverse datasets, identifying patterns, and enabling precision medicine strategies. Over the past decade, applications of AI in ophthalmology have expanded from imaging-based diagnostics to molecular-level modeling, bridging critical gaps in understanding disease mechanisms. This paper systematically reviews the application of AI-driven methods, including reinforcement learning (RL), graph neural networks (GNNs), Bayesian inference, and generative adversarial networks (GANs), in the context of these ophthalmic conditions. RL models simulate transcription factor dynamics in hypoxic or inflammatory environments, offering insights into disrupted molecular pathways. GNNs map intricate molecular networks within affected tissues, identifying key inflammatory or degenerative drivers. Bayesian inference provides probabilistic models for predicting disease progression and response to therapies, while GANs generate synthetic datasets to explore therapeutic interventions. By contextualizing these AI tools within the broader framework of ophthalmic disease management, this review highlights their potential to transform diagnostic precision and therapeutic outcomes. Ultimately, this work underscores the need for continued interdisciplinary collaboration to harness AI’s potential in advancing the field of ophthalmology and improving patient care. Full article

(This article belongs to the Special Issue Translational AI and Computational Tools for Ophthalmic Disease)

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3 pages, 130 KiB

Open AccessEditor’s ChoiceEditorial

Editorial: Biomechanics, Health, Disease and Rehabilitation—2nd Edition

by Redha Taiar

Bioengineering 2025, 12(2), 121; https://doi.org/10.3390/bioengineering12020121 - 28 Jan 2025

Viewed by 683

Abstract

In the original article [...] Full article

(This article belongs to the Special Issue Biomechanics, Health, Disease and Rehabilitation, 2nd Edition)

17 pages, 7767 KiB

Open AccessEditor’s ChoiceArticle

A Novel Mechanics-Based Design for Overcorrection in Clear Aligner Orthodontics via Finite Element Analysis

by Sensen Yang and Yumin Cheng

Bioengineering 2025, 12(2), 110; https://doi.org/10.3390/bioengineering12020110 - 24 Jan 2025

Viewed by 925

Abstract

A simplified mechanics model of aligner–tooth interaction was developed to establish a precise computational method for overcorrection design in clear aligner orthodontics. Validated through finite element analysis and experiments, the results demonstrated that designing the movement of only the target teeth on the [...] Read more.

A simplified mechanics model of aligner–tooth interaction was developed to establish a precise computational method for overcorrection design in clear aligner orthodontics. Validated through finite element analysis and experiments, the results demonstrated that designing the movement of only the target teeth on the aligner leads to uneven force distribution on adjacent teeth, while an overcorrection design can evenly distribute the reaction force generated by pushing the target teeth to the anchorage teeth, reducing the maximum force on the anchorage teeth, minimizing unplanned tooth movement, and improving the efficacy of the designed tooth movement for all teeth. Full article

(This article belongs to the Special Issue Orthodontic Biomechanics)

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31 pages, 1806 KiB

Open AccessEditor’s ChoiceReview

Emerging Strategies for Revascularization: Use of Cell-Derived Extracellular Vesicles and Artificial Nanovesicles in Critical Limb Ischemia

by Vijay Murali Ravi Mythili, Ramya Lakshmi Rajendran, Raksa Arun, Vasanth Kanth Thasma Loganathbabu, Danyal Reyaz, ArulJothi Kandasamy Nagarajan, Byeong-Cheol Ahn and Prakash Gangadaran

Bioengineering 2025, 12(1), 92; https://doi.org/10.3390/bioengineering12010092 - 20 Jan 2025

Cited by 2 | Viewed by 1230

Abstract

Critical limb ischemia (CLI) poses a substantial and intricate challenge in vascular medicine, necessitating the development of innovative therapeutic strategies to address its multifaceted pathophysiology. Conventional revascularization approaches often fail to adequately address the complexity of CLI, necessitating the identification of alternative methodologies. [...] Read more.

Critical limb ischemia (CLI) poses a substantial and intricate challenge in vascular medicine, necessitating the development of innovative therapeutic strategies to address its multifaceted pathophysiology. Conventional revascularization approaches often fail to adequately address the complexity of CLI, necessitating the identification of alternative methodologies. This review explores uncharted territory beyond traditional therapies, focusing on the potential of two distinct yet interrelated entities: cell-derived extracellular vesicles (EVs) and artificial nanovesicles. Cell-derived EVs are small membranous structures naturally released by cells, and artificial nanovesicles are artificially engineered nanosized vesicles. Both these vesicles represent promising avenues for therapeutic intervention. They act as carriers of bioactive cargo, including proteins, nucleic acids, and lipids, that can modulate intricate cellular responses associated with ischemic tissue repair and angiogenesis. This review also assesses the evolving landscape of CLI revascularization through the unique perspective of cell-derived EVs and artificial nanovesicles. The review spans the spectrum from early preclinical investigations to the latest translational advancements, providing a comprehensive overview of the current state of research in this emerging field. These groundbreaking vesicle therapies hold immense potential for revolutionizing CLI treatment paradigms. Full article

(This article belongs to the Special Issue Innovations in Regenerative Therapy: Cell and Cell-Free Approaches)

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28 pages, 11306 KiB

Open AccessEditor’s ChoiceArticle

Biomarker Investigation Using Multiple Brain Measures from MRI Through Explainable Artificial Intelligence in Alzheimer’s Disease Classification

by Davide Coluzzi, Valentina Bordin, Massimo W. Rivolta, Igor Fortel, Liang Zhan, Alex Leow and Giuseppe Baselli

Bioengineering 2025, 12(1), 82; https://doi.org/10.3390/bioengineering12010082 - 17 Jan 2025

Cited by 2 | Viewed by 1532

Abstract

As the leading cause of dementia worldwide, Alzheimer’s Disease (AD) has prompted significant interest in developing Deep Learning (DL) approaches for its classification. However, it currently remains unclear whether these models rely on established biological indicators. This work compares a novel DL model [...] Read more.

As the leading cause of dementia worldwide, Alzheimer’s Disease (AD) has prompted significant interest in developing Deep Learning (DL) approaches for its classification. However, it currently remains unclear whether these models rely on established biological indicators. This work compares a novel DL model using structural connectivity (namely, BC-GCN-SE adapted from functional connectivity tasks) with an established model using structural magnetic resonance imaging (MRI) scans (namely, ResNet18). Unlike most studies primarily focusing on performance, our work places explainability at the forefront. Specifically, we define a novel Explainable Artificial Intelligence (XAI) metric, based on gradient-weighted class activation mapping. Its aim is quantitatively measuring how effectively these models fare against established AD biomarkers in their decision-making. The XAI assessment was conducted across 132 brain parcels. Results were compared to AD-relevant regions to measure adherence to domain knowledge. Then, differences in explainability patterns between the two models were assessed to explore the insights offered by each piece of data (i.e., MRI vs. connectivity). Classification performance was satisfactory in terms of both the median true positive (ResNet18: 0.817, BC-GCN-SE: 0.703) and true negative rates (ResNet18: 0.816; BC-GCN-SE: 0.738). Statistical tests (p < 0.05) and ranking of the 15% most relevant parcels revealed the involvement of target areas: the medial temporal lobe for ResNet18 and the default mode network for BC-GCN-SE. Additionally, our findings suggest that different imaging modalities provide complementary information to DL models. This lays the foundation for bioengineering advancements in developing more comprehensive and trustworthy DL models, potentially enhancing their applicability as diagnostic support tools for neurodegenerative diseases. Full article

(This article belongs to the Special Issue Machine-Learning-Driven Medical Image Analysis)

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13 pages, 2212 KiB

Open AccessEditor’s ChoiceArticle

Effect of Adapted Ergometer Setup and Rowing Speed on Lower Extremity Loading in People with and Without Spinal Cord Injury

by Ying Fang and Karen L. Troy

Bioengineering 2025, 12(1), 75; https://doi.org/10.3390/bioengineering12010075 - 15 Jan 2025

Viewed by 785

Abstract

Background: Functional electrical stimulation-assisted rowing (FES rowing) is a rehabilitation exercise used to prevent disuse osteoporosis, which is common in people with spinal cord injury (SCI). However, its effect on bone loss prevention varied in SCI patients, potentially due to inconsistent loading. This [...] Read more.

Background: Functional electrical stimulation-assisted rowing (FES rowing) is a rehabilitation exercise used to prevent disuse osteoporosis, which is common in people with spinal cord injury (SCI). However, its effect on bone loss prevention varied in SCI patients, potentially due to inconsistent loading. This study investigates the effect of ergometer setup and rowing speed on lower extremity loading during rowing. Methods: Twenty able-bodied participants and one participant with SCI rowed on an adapted ergometer with different speeds and setups. We calculated foot reaction force and knee moment for all participants, and tibiofemoral force for the rower with SCI. Results: Able-bodied rowers generated 0.22–0.45 body weight (BW) foot reaction forces, and a higher force was associated with a fast speed, forward seat position, and large knee range of motion (RoM). The rower with SCI had the greatest foot reaction force (0.39 BW) when rowing with a small knee RoM at a rear seat position, and the highest tibiofemoral force (2.23 BW) with a large knee RoM or at a rear seat position. Conclusions: Ergometer setup and speed both affect lower limb loading and should be further studied in more rowers with SCI. This can inform rehabilitation protocols to standardize ergometer configuration to improve bone health. Full article

(This article belongs to the Special Issue Biomechanics of Orthopaedic Rehabilitation)

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20 pages, 1270 KiB

Open AccessEditor’s ChoiceReview

Current Understanding on the Heterogenous Expression of Plastic Depolymerising Enzymes in Pichia pastoris

by Shuyan Wu, David Hooks and Gale Brightwell

Bioengineering 2025, 12(1), 68; https://doi.org/10.3390/bioengineering12010068 - 14 Jan 2025

Viewed by 1071

Abstract

Enzymatic depolymerisation is increasingly recognised as a reliable and environmentally friendly method. The development of this technology hinges on the availability of high-quality enzymes and associated bioreaction systems for upscaling biodegradation. Microbial heterologous expression systems have been studied for meeting this demand. Among [...] Read more.

Enzymatic depolymerisation is increasingly recognised as a reliable and environmentally friendly method. The development of this technology hinges on the availability of high-quality enzymes and associated bioreaction systems for upscaling biodegradation. Microbial heterologous expression systems have been studied for meeting this demand. Among these systems, the Pichia pastoris expression system has emerged as a widely used platform for producing secreted heterologous proteins. This article provides an overview of studies involving the recombinant expression of polymer-degrading enzymes using the P. pastoris expression system. Research on P. pastoris expression of interested enzymes with depolymerising ability, including cutinase, lipase, and laccase, are highlighted in the review. The key factors influencing the heterologous expression of polymer-degrading enzymes in P. pastoris are discussed, shedding light on the challenges and opportunities in the development of depolymerising biocatalysts through the P. pastoris expression system. Full article

(This article belongs to the Special Issue Synthetic Biology and Bioprocess Engineering for High-Value Compounds)

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19 pages, 5155 KiB

Open AccessEditor’s ChoiceArticle

Ex Vivo Regional Gene Therapy Compared to Recombinant BMP-2 for the Treatment of Critical-Size Bone Defects: An In Vivo Single-Cell RNA-Sequencing Study

by Arijita Sarkar, Matthew C. Gallo, Jennifer A. Bell, Cory K. Mayfield, Jacob R. Ball, Mina Ayad, Elizabeth Lechtholz-Zey, Stephanie W. Chang, Osamu Sugiyama, Denis Evseenko and Jay R. Lieberman

Bioengineering 2025, 12(1), 29; https://doi.org/10.3390/bioengineering12010029 - 1 Jan 2025

Viewed by 1380

Abstract

Ex vivo regional gene therapy is a promising tissue-engineering strategy for bone regeneration: osteogenic mesenchymal stem cells (MSCs) can be genetically modified to express an osteoinductive stimulus (e.g., bone morphogenetic protein-2), seeded onto an osteoconductive scaffold, and then implanted into a bone defect [...] Read more.

Ex vivo regional gene therapy is a promising tissue-engineering strategy for bone regeneration: osteogenic mesenchymal stem cells (MSCs) can be genetically modified to express an osteoinductive stimulus (e.g., bone morphogenetic protein-2), seeded onto an osteoconductive scaffold, and then implanted into a bone defect to exert a therapeutic effect. Compared to recombinant human BMP-2 (rhBMP-2), which is approved for clinical use, regional gene therapy may have unique benefits related to the addition of MSCs and the sustained release of BMP-2. However, the cellular and transcriptional mechanisms regulating the response to these two strategies for BMP-2 mediated bone regeneration are largely unknown. Here, for the first time, we performed single-cell RNA sequencing (10x Genomics) of hematoma tissue in six rats with critical-sized femoral defects that were treated with either regional gene therapy or rhBMP-2. Our unbiased bioinformatic analysis of 2393 filtered cells in each group revealed treatment-specific differences in their cellular composition, transcriptional profiles, and cellular communication patterns. Gene therapy treatment induced a more robust chondrogenic response, as well as a decrease in the proportion of fibroblasts and the expression of profibrotic pathways. Additionally, gene therapy was associated with an anti-inflammatory microenvironment; macrophages expressing canonical anti-inflammatory markers were more common in the gene therapy group. In contrast, pro-inflammatory markers were more highly expressed in the rhBMP-2 group. Collectively, the results of our study may offer insights into the unique pathways through which ex vivo regional gene therapy can augment bone regeneration compared to rhBMP-2. Furthermore, an improved understanding of the cellular pathways involved in segmental bone defect healing may allow for the further optimization of regional gene therapy or other bone repair strategies. Full article

(This article belongs to the Special Issue Advances in Bone Regeneration with Multipotential Stromal Cells and Bioactive Materials)

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15 pages, 3329 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Thigh Muscle Forces on Knee Contact Force in Female Patients with Severe Knee Osteoarthritis

by Tingting Liu, Hao Xie, Songhua Yan, Jizhou Zeng and Kuan Zhang

Bioengineering 2024, 11(12), 1299; https://doi.org/10.3390/bioengineering11121299 - 20 Dec 2024

Viewed by 896

Abstract

Thigh muscles greatly influence knee joint loading, and abnormal loading significantly contributes to the progression of knee osteoarthritis (KOA). Muscle weakness in KOA patients is common, but the specific contribution of each thigh muscle to joint loading is unclear. The gait data from [...] Read more.

Thigh muscles greatly influence knee joint loading, and abnormal loading significantly contributes to the progression of knee osteoarthritis (KOA). Muscle weakness in KOA patients is common, but the specific contribution of each thigh muscle to joint loading is unclear. The gait data from 10 severe female KOA patients and 10 controls were collected, and the maximum isometric forces of the biceps femoris long head (BFL), semitendinosus (ST), rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) were calibrated via ultrasound. Four musculoskeletal (MSK) models were developed based on EMG-assisted optimization, static optimization, and ultrasound data. The ultrasound-calibrated EMG-assisted MSK model achieved higher accuracy (R² > 0.97, RMSE < 0.045 Nm/kg). Patients exhibited increased VL and VM forces (p < 0.004) and decreased RF force (p < 0.006), along with elevated medial and total joint contact forces (p < 0.001) and reduced lateral forces (p < 0.001) compared to controls. The affected side relied on VL and BFL the most (p < 0.042), while RF was key for the unaffected side (p < 0.003). Ultrasound calibration and EMG-assisted optimization significantly enhanced MSK model accuracy. Patients exerted greater quadriceps and hamstring forces bilaterally, shifting knee loading medially, and depended more on the lateral thigh muscles on the affected side. Hamstrings contributed more to joint contact forces, while quadriceps’ contributions decreased. Full article

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

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17 pages, 5821 KiB

Open AccessEditor’s ChoiceArticle

Development of a Microfluidic Viscometer for Non-Newtonian Blood Analog Fluid Analysis

by Yii-Nuoh Chang and Da-Jeng Yao

Bioengineering 2024, 11(12), 1298; https://doi.org/10.3390/bioengineering11121298 - 20 Dec 2024

Viewed by 4484

Abstract

The incidence of stroke is on the rise globally. This affects one in every four individuals each year, underscoring the urgent need for early warning and prevention systems. The existing research highlights the significance of monitoring blood viscosity in stroke risk evaluations. However, [...] Read more.

The incidence of stroke is on the rise globally. This affects one in every four individuals each year, underscoring the urgent need for early warning and prevention systems. The existing research highlights the significance of monitoring blood viscosity in stroke risk evaluations. However, the current methods lack the precision to measure viscosity under low shear rate conditions (<100 s⁻¹), which are observed during pulsatility flow. This study addresses this gap by introducing a novel microfluidic platform designed to measure blood viscosity with high precision under pulsatility flow conditions. The systolic blood viscosity (SBV) and diastolic blood viscosity (DBV) can be differentiated and evaluated by using this system. The non-Newtonian behavior of blood is captured across specific shear rate conditions. The platform employs a meticulously designed microarray to simulate the variations in blood viscosity during pulsation within blood vessels.The results demonstrate an impressive accuracy of 95% and excellent reproducibility when compared to traditional viscometers and rheometers and are within the human blood viscosity range of 1–10 cP. This monitoring system holds promise as a valuable addition to stroke risk evaluation methods, with the potential to enhance prediction accuracy. Full article

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

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12 pages, 1677 KiB

Open AccessEditor’s ChoiceReview

Microfluidic Technology for Measuring Mechanical Properties of Single Cells and Its Application

by Yixin Yin and Ziyuan Liu

Bioengineering 2024, 11(12), 1266; https://doi.org/10.3390/bioengineering11121266 - 13 Dec 2024

Cited by 1 | Viewed by 1134

Abstract

Cellular mechanical properties are critical for tissue and organ homeostasis, which are associated with many diseases and are very promising non-labeled biomarkers. Over the past two decades, many research tools based on microfluidic methods have been developed to measure the biophysical properties of [...] Read more.

Cellular mechanical properties are critical for tissue and organ homeostasis, which are associated with many diseases and are very promising non-labeled biomarkers. Over the past two decades, many research tools based on microfluidic methods have been developed to measure the biophysical properties of single cells; however, it has still not been possible to develop a technique that allows for high-throughput, easy-to-operate and precise measurements of single-cell biophysical properties. In this paper, we review the emerging technologies implemented based on microfluidic approaches for characterizing the mechanical properties of single cells and discuss the methodological principles, advantages, limitations, and applications of various technologies. Full article

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

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16 pages, 5144 KiB

Open AccessEditor’s ChoiceSystematic Review

Progress in 3D Printing Applications for the Management of Orbital Disorders: A Systematic Review

by Luca Michelutti, Alessandro Tel, Massimo Robiony, Salvatore Sembronio, Riccardo Nocini, Edoardo Agosti, Tamara Ius, Caterina Gagliano and Marco Zeppieri

Bioengineering 2024, 11(12), 1238; https://doi.org/10.3390/bioengineering11121238 - 7 Dec 2024

Cited by 2 | Viewed by 1124

Abstract

Introduction: 3D printing technology has gained considerable interest in the domain of orbital illnesses owing to its capacity to transform diagnosis, surgery planning, and treatment. This systematic review seeks to deliver a thorough examination of the contemporary applications of 3D printing in [...] Read more.

Introduction: 3D printing technology has gained considerable interest in the domain of orbital illnesses owing to its capacity to transform diagnosis, surgery planning, and treatment. This systematic review seeks to deliver a thorough examination of the contemporary applications of 3D printing in the treatment of ocular problems, encompassing tumors, injuries, and congenital defects. This systematic review of recent studies has examined the application of patient-specific 3D-printed models for preoperative planning, personalized implants, and prosthetics. Methods: This systematic review was conducted according to the PRISMA guidelines. The PICOS is “What are the current advances and applications of 3D printing for the management of orbital pathology?” The databases analyzed for the research phase are MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, ScienceDirect, Scopus, CINAHL, and Web of Science. Results: Out of 314 studies found in the literature, only 12 met the inclusion and exclusion criteria. From the included studies, it is evident that 3D printing can be a useful technology for the management of trauma and oncological pathologies of the orbital region. Discussion: 3D printing proves to be very useful mainly for the purpose of improving the preoperative planning of a surgical procedure, allowing for better preparation by the surgical team and a reduction in operative time and complications. Conclusions: 3D printing has proven to be an outstanding tool in the management of orbit pathology. Comparing the advantages and disadvantages of such technology, the former far outweigh the latter. Full article

(This article belongs to the Special Issue New Sights of Biomaterials and Regenerative Medicine)

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12 pages, 576 KiB

Open AccessEditor’s ChoiceArticle

The Effect of EEG Biofeedback Training Frequency and Environmental Conditions on Simple and Complex Reaction Times

by Skalski Dariusz, Maciej Kostrzewa, Prończuk Magdalena, Jarosław Markowski, Jan Pilch, Marcin Żak and Adam Maszczyk

Bioengineering 2024, 11(12), 1208; https://doi.org/10.3390/bioengineering11121208 - 29 Nov 2024

Cited by 2 | Viewed by 1027

Abstract

The objective of this study is to evaluate the impact of EEG biofeedback training under normoxic and normobaric hypoxic conditions on both simple and complex reaction times in judo athletes, and to identify the optimal training frequency and environmental conditions that substantially enhance [...] Read more.

The objective of this study is to evaluate the impact of EEG biofeedback training under normoxic and normobaric hypoxic conditions on both simple and complex reaction times in judo athletes, and to identify the optimal training frequency and environmental conditions that substantially enhance reaction times in the examined athlete groups. The study comprised 20 male judo athlete members of the Polish national judo team in the middleweight and heavyweight categories. We randomly assigned participants to an experimental group and a control group. We conducted the research over four cycles, varying the frequency of EEG biofeedback sessions and environmental circumstances for both the experimental and control groups. Every research cycle had 15 training sessions. The results showed that the experimental group, following the theta/beta regimen, got significantly faster at complex reactions after a training cycle that included sessions every other day at normal oxygen levels. Following daily training sessions in normoxic circumstances, we noted enhancements in simple reaction speeds. Under normobaric hypoxia conditions, the judo athletes showed deterioration in both simple and complex reaction times. The control group showed no similar changes. Daily EEG training in normoxic settings markedly improved simple reaction time, but EEG-BF training conducted every other day greatly raised complicated reaction time. In contrast, training under normobaric hypoxia settings did not result in enhancements in basic or complicated reaction times following EEG training. Full article

(This article belongs to the Special Issue New Sights of EEG and Brain Diseases: Updates and Directions)

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3 pages, 153 KiB

Open AccessEditor’s ChoiceEditorial

Computational Fluid Dynamics in Medicine and Biology

by Amirtahà Taebi

Bioengineering 2024, 11(11), 1168; https://doi.org/10.3390/bioengineering11111168 - 20 Nov 2024

Viewed by 1188

Abstract

This Special Issue of Bioengineering presents cutting-edge research on the applications of computational fluid dynamics (CFD) in medical and biological contexts [...] Full article

(This article belongs to the Special Issue Computational Fluid Dynamics in Medicine and Biology)

30 pages, 8578 KiB

Open AccessEditor’s ChoiceArticle

Around-Body Versus On-Body Motion Sensing: A Comparison of Efficacy Across a Range of Body Movements and Scales

by Katelyn Rohrer, Luis De Anda, Camila Grubb, Zachary Hansen, Jordan Rodriguez, Greyson St Pierre, Sara Sheikhlary, Suleyman Omer, Binh Tran, Mehrail Lawendy, Farah Alqaraghuli, Chris Hedgecoke, Youssif Abdelkeder, Rebecca C. Slepian, Ethan Ross, Ryan Chung and Marvin J. Slepian

Bioengineering 2024, 11(11), 1163; https://doi.org/10.3390/bioengineering11111163 - 19 Nov 2024

Viewed by 1029

Abstract

Motion is vital for life. Currently, the clinical assessment of motion abnormalities is largely qualitative. We previously developed methods to quantitatively assess motion using visual detection systems (around-body) and stretchable electronic sensors (on-body). Here we compare the efficacy of these methods across predefined [...] Read more.

Motion is vital for life. Currently, the clinical assessment of motion abnormalities is largely qualitative. We previously developed methods to quantitatively assess motion using visual detection systems (around-body) and stretchable electronic sensors (on-body). Here we compare the efficacy of these methods across predefined motions, hypothesizing that the around-body system detects motion with similar accuracy as on-body sensors. Six human volunteers performed six defined motions covering three excursion lengths, small, medium, and large, which were analyzed via both around-body visual marker detection (MoCa version 1.0) and on-body stretchable electronic sensors (BioStamp version 1.0). Data from each system was compared as to the extent of trackability and comparative efficacy between systems. Both systems successfully detected motions, allowing quantitative analysis. Angular displacement between systems had the highest agreement efficiency for the bicep curl and body lean motion, with 73.24% and 65.35%, respectively. The finger pinch motion had an agreement efficiency of 36.71% and chest abduction/adduction had 45.55%. Shoulder abduction/adduction and shoulder flexion/extension motions had the lowest agreement efficiencies with 24.49% and 26.28%, respectively. MoCa was comparable to BioStamp in terms of angular displacement, though velocity and linear speed output could benefit from additional processing. Our findings demonstrate comparable efficacy for non-contact motion detection to that of on-body sensor detection, and offers insight as to the best system selection for specific clinical uses based on the use-case of the desired motion being analyzed. Full article

(This article belongs to the Special Issue Biomechanics and Motion Analysis)

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9 pages, 2282 KiB

Open AccessEditor’s ChoiceArticle

Computational Fluid Dynamic Optimization of Micropatterned Surfaces: Towards Biofunctionalization of Artificial Organs

by Wenxuan He, Aminat M. Ibrahim, Abhishek Karmakar, Shivani Tuli, Jonathan T. Butcher and James F. Antaki

Bioengineering 2024, 11(11), 1092; https://doi.org/10.3390/bioengineering11111092 - 30 Oct 2024

Viewed by 1179

Abstract

Modifying surface topography to prevent surface-induced thrombosis in cardiovascular implants allows endothelialization, which is the natural thrombo-resistance of blood-contacting surfaces, and is deemed to be the only long-term solution for hemocompatible materials. We adapted a simulation framework to predict platelet deposition on a [...] Read more.

Modifying surface topography to prevent surface-induced thrombosis in cardiovascular implants allows endothelialization, which is the natural thrombo-resistance of blood-contacting surfaces, and is deemed to be the only long-term solution for hemocompatible materials. We adapted a simulation framework to predict platelet deposition on a modified surface and developed an optimization strategy to promote endothelial retention and limit platelet deposition. Under supraphysiological bulk shear stress, a maximum of 79% linear coverage was achieved. This study concludes that the addition of microtrenches promotes endothelial retention and can be improved through the optimal selection of geometric parameters. Full article

(This article belongs to the Special Issue Engineered Analysis of Tissue Mechanics and Blood Flow for Cardiovascular Host-Device Interaction)

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5 pages, 184 KiB

Open AccessEditor’s ChoiceEditorial

Interdisciplinary Innovations and Applications of Bionics and Bioengineering in Kinesiology

by Wei-Hsun Tai, Wenjian Wu, Haibin Yu and Rui Zhang

Bioengineering 2024, 11(10), 1042; https://doi.org/10.3390/bioengineering11101042 - 18 Oct 2024

Viewed by 1600

Abstract

Kinesiology, as an interdisciplinary field, emphasizes the study of human physical activity, with a particular focus on biomechanics and sports science [...] Full article

(This article belongs to the Special Issue Biomechanics and Bionics in Sport and Exercise, Volume II)

15 pages, 2088 KiB

Open AccessEditor’s ChoiceReview

The Psychological Nature of Female Gait Attractiveness

by Hiroko Tanabe and Kota Yamamoto

Bioengineering 2024, 11(10), 1037; https://doi.org/10.3390/bioengineering11101037 - 17 Oct 2024

Cited by 1 | Viewed by 1851

Abstract

Walking, a basic physical movement of the human body, is a resource for observers in forming interpersonal impressions. We have previously investigated the expression and perception of the attractiveness of female gaits. In this paper, drawing on our previous research, additional analysis, and [...] Read more.

Walking, a basic physical movement of the human body, is a resource for observers in forming interpersonal impressions. We have previously investigated the expression and perception of the attractiveness of female gaits. In this paper, drawing on our previous research, additional analysis, and reviewing previous studies, we seek to deepen our understanding of the function of gait attractiveness. First, we review previous research on gait as nonverbal information. Then, we show that fashion models’ gaits reflect sociocultural genderlessness, while nonmodels express reproductive-related biological attractiveness. Next, we discuss the functions of gait attractiveness based on statistical models that link gait parameters and attractiveness scores. Finally, we focus on observers’ perception of attractiveness, constructing a model of the visual information processing with respect to gait attractiveness. Overall, our results suggest that there are not only biological but also sociocultural criteria for gait attractiveness, and men and women place greater importance on the former and latter criteria, respectively, when assessing female gait attractiveness. This paper forms a major step forward in neuroaesthetics to understand the beauty of the human body and the generation of biological motions. Full article

(This article belongs to the Special Issue Bioengineering of the Motor System)

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22 pages, 2282 KiB

Open AccessEditor’s ChoiceArticle

Emotion Recognition Using EEG Signals and Audiovisual Features with Contrastive Learning

by Ju-Hwan Lee, Jin-Young Kim and Hyoung-Gook Kim

Bioengineering 2024, 11(10), 997; https://doi.org/10.3390/bioengineering11100997 - 3 Oct 2024

Cited by 2 | Viewed by 2614

Abstract

Multimodal emotion recognition has emerged as a promising approach to capture the complex nature of human emotions by integrating information from various sources such as physiological signals, visual behavioral cues, and audio-visual content. However, current methods often struggle with effectively processing redundant or [...] Read more.

Multimodal emotion recognition has emerged as a promising approach to capture the complex nature of human emotions by integrating information from various sources such as physiological signals, visual behavioral cues, and audio-visual content. However, current methods often struggle with effectively processing redundant or conflicting information across modalities and may overlook implicit inter-modal correlations. To address these challenges, this paper presents a novel multimodal emotion recognition framework which integrates audio-visual features with viewers’ EEG data to enhance emotion classification accuracy. The proposed approach employs modality-specific encoders to extract spatiotemporal features, which are then aligned through contrastive learning to capture inter-modal relationships. Additionally, cross-modal attention mechanisms are incorporated for effective feature fusion across modalities. The framework, comprising pre-training, fine-tuning, and testing phases, is evaluated on multiple datasets of emotional responses. The experimental results demonstrate that the proposed multimodal approach, which combines audio-visual features with EEG data, is highly effective in recognizing emotions, highlighting its potential for advancing emotion recognition systems. Full article

(This article belongs to the Special Issue Recent Advances in Machine Learning and Explainable Artificial Intelligence in Biomedical Data Mining, and Disease Diagnosis Frameworks)

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33 pages, 3011 KiB

Open AccessEditor’s ChoiceReview

Building an Ethical and Trustworthy Biomedical AI Ecosystem for the Translational and Clinical Integration of Foundation Models

by Baradwaj Simha Sankar, Destiny Gilliland, Jack Rincon, Henning Hermjakob, Yu Yan, Irsyad Adam, Gwyneth Lemaster, Dean Wang, Karol Watson, Alex Bui, Wei Wang and Peipei Ping

Bioengineering 2024, 11(10), 984; https://doi.org/10.3390/bioengineering11100984 - 29 Sep 2024

Cited by 3 | Viewed by 3644

Abstract

Foundation Models (FMs) are gaining increasing attention in the biomedical artificial intelligence (AI) ecosystem due to their ability to represent and contextualize multimodal biomedical data. These capabilities make FMs a valuable tool for a variety of tasks, including biomedical reasoning, hypothesis generation, and [...] Read more.

Foundation Models (FMs) are gaining increasing attention in the biomedical artificial intelligence (AI) ecosystem due to their ability to represent and contextualize multimodal biomedical data. These capabilities make FMs a valuable tool for a variety of tasks, including biomedical reasoning, hypothesis generation, and interpreting complex imaging data. In this review paper, we address the unique challenges associated with establishing an ethical and trustworthy biomedical AI ecosystem, with a particular focus on the development of FMs and their downstream applications. We explore strategies that can be implemented throughout the biomedical AI pipeline to effectively tackle these challenges, ensuring that these FMs are translated responsibly into clinical and translational settings. Additionally, we emphasize the importance of key stewardship and co-design principles that not only ensure robust regulation but also guarantee that the interests of all stakeholders—especially those involved in or affected by these clinical and translational applications—are adequately represented. We aim to empower the biomedical AI community to harness these models responsibly and effectively. As we navigate this exciting frontier, our collective commitment to ethical stewardship, co-design, and responsible translation will be instrumental in ensuring that the evolution of FMs truly enhances patient care and medical decision-making, ultimately leading to a more equitable and trustworthy biomedical AI ecosystem. Full article

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

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6 pages, 213 KiB

Open AccessEditor’s ChoiceEditorial

Microalgae Biotechnology: Methods and Applications

by Xianmin Wang, Songlin Ma and Fantao Kong

Bioengineering 2024, 11(10), 965; https://doi.org/10.3390/bioengineering11100965 - 26 Sep 2024

Cited by 3 | Viewed by 2364

Abstract

Microalgae are regarded as sustainable and promising chassis for biotechnology due to their efficient photosynthesis and ability to convert CO₂ into valuable products [...] Full article

(This article belongs to the Section Biochemical Engineering)

15 pages, 1321 KiB

Open AccessEditor’s ChoiceCommentary

The Use of Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles in the Treatment of Osteoarthritis: Insights from Preclinical Studies

by Mitch Jones, Elena Jones and Dimitrios Kouroupis

Bioengineering 2024, 11(10), 961; https://doi.org/10.3390/bioengineering11100961 - 26 Sep 2024

Cited by 1 | Viewed by 1672

Abstract

Osteoarthritis (OA) is a prominent cause of disability, and has severe social and economic ramifications across the globe. The main driver of OA’s pervasiveness is the fact that no current medical interventions exist to reverse or even attenuate the degeneration of cartilage within [...] Read more.

Osteoarthritis (OA) is a prominent cause of disability, and has severe social and economic ramifications across the globe. The main driver of OA’s pervasiveness is the fact that no current medical interventions exist to reverse or even attenuate the degeneration of cartilage within the articular joint. Crucial for cell-to-cell communication, extracellular vesicles (EVs) contribute to OA progression through the delivery of bioactive molecules in the inflammatory microenvironment. By repurposing this acellular means of signal transmission, therapeutic drugs may be administered to degenerated cartilage tissue in the hopes of encouraging regeneration. Positive outcomes are apparent in in vivo studies on this subject; however, for this therapy to prove itself in the clinical world, efforts towards standardizing the characterization, application, biological contents, and dosage are essential. Full article

(This article belongs to the Section Regenerative Engineering)

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23 pages, 6104 KiB

Open AccessEditor’s ChoiceArticle

Mesenchymal Stem Cell-Conditioned Media-Loaded Microparticles Enhance Acute Patency in Silk-Based Vascular Grafts

by Katherine L. Lorentz, Ande X. Marini, Liza A. Bruk, Prerak Gupta, Biman B. Mandal, Morgan V. DiLeo, Justin S. Weinbaum, Steven R. Little and David A. Vorp

Bioengineering 2024, 11(9), 947; https://doi.org/10.3390/bioengineering11090947 - 21 Sep 2024

Cited by 1 | Viewed by 2372

Abstract

Coronary artery disease leads to over 360,000 deaths annually in the United States, and off-the-shelf bypass graft options are currently limited and/or have high failure rates. Tissue-engineered vascular grafts (TEVGs) present an attractive option, though the promising mesenchymal stem cell (MSC)-based implants face [...] Read more.

Coronary artery disease leads to over 360,000 deaths annually in the United States, and off-the-shelf bypass graft options are currently limited and/or have high failure rates. Tissue-engineered vascular grafts (TEVGs) present an attractive option, though the promising mesenchymal stem cell (MSC)-based implants face uncertain regulatory pathways. In this study, “artificial MSCs” (ArtMSCs) were fabricated by encapsulating MSC-conditioned media (CM) in poly(lactic-co-glycolic acid) microparticles. ArtMSCs and control microparticles (Blank-MPs) were incubated over 7 days to assess the release of total protein and the vascular endothelial growth factor (VEGF-A); releasates were also assessed for cytotoxicity and promotion of smooth muscle cell (SMC) proliferation. Each MP type was loaded in previously published “lyogel” silk scaffolds and implanted as interposition grafts in Lewis rats for 1 or 8 weeks. Explanted grafts were assessed for patency and cell content. ArtMSCs had a burst release of protein and VEGF-A. CM increased proliferation in SMCs, but not after encapsulation. TEVG explants after 1 week had significantly higher patency rates with ArtMSCs compared to Blank-MPs, but similar to unseeded lyogel grafts. ArtMSC explants had lower numbers of infiltrating macrophages compared to Blank-MP explants, suggesting a modulation of inflammatory response by the ArtMSCs. TEVG explants after 8 weeks showed no significant difference in patency among the three groups. The ArtMSC explants showed higher numbers of SMCs and endothelial cells within the neotissue layer of the graft compared to Blank-MP explants. In sum, while the ArtMSCs had positive effects acutely, efficacy was lost in the longer term; therefore, further optimization is needed. Full article

(This article belongs to the Section Regenerative Engineering)

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15 pages, 1570 KiB

Open AccessEditor’s ChoiceArticle

Machine Learning-Driven Prediction of Brain Age for Alzheimer’s Risk: APOE4 Genotype and Gender Effects

by Carter Woods, Xin Xing, Subash Khanal and Ai-Ling Lin

Bioengineering 2024, 11(9), 943; https://doi.org/10.3390/bioengineering11090943 - 20 Sep 2024

Viewed by 2477

Abstract

Background: Alzheimer’s disease (AD) is a leading cause of dementia, and it is significantly influenced by the apolipoprotein E4 (APOE4) gene and gender. This study aimed to use machine learning (ML) algorithms to predict brain age and assess AD risk by considering the [...] Read more.

Background: Alzheimer’s disease (AD) is a leading cause of dementia, and it is significantly influenced by the apolipoprotein E4 (APOE4) gene and gender. This study aimed to use machine learning (ML) algorithms to predict brain age and assess AD risk by considering the effects of the APOE4 genotype and gender. Methods: We collected brain volumetric MRI data and medical records from 1100 cognitively unimpaired individuals and 602 patients with AD. We applied three ML regression models—XGBoost, random forest (RF), and linear regression (LR)—to predict brain age. Additionally, we introduced two novel metrics, brain age difference (BAD) and integrated difference (ID), to evaluate the models’ performances and analyze the influences of the APOE4 genotype and gender on brain aging. Results: Patients with AD displayed significantly older brain ages compared to their chronological ages, with BADs ranging from 6.5 to 10 years. The RF model outperformed both XGBoost and LR in terms of accuracy, delivering higher ID values and more precise predictions. Comparing the APOE4 carriers with noncarriers, the models showed enhanced ID values and consistent brain age predictions, improving the overall performance. Gender-specific analyses indicated slight enhancements, with the models performing equally well for both genders. Conclusions: This study demonstrates that robust ML models for brain age prediction can play a crucial role in the early detection of AD risk through MRI brain structural imaging. The significant impact of the APOE4 genotype on brain aging and AD risk is also emphasized. These findings highlight the potential of ML models in assessing AD risk and suggest that utilizing AI for AD identification could enable earlier preventative interventions. Full article

(This article belongs to the Special Issue Recent Advances in Biomedical Imaging: 2nd Edition)

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10 pages, 2484 KiB

Open AccessEditor’s ChoiceArticle

Thermal Evaluation of Bone Drilling: Assessing Drill Bits and Sequential Drilling

by Sihana Rugova and Marcus Abboud

Bioengineering 2024, 11(9), 928; https://doi.org/10.3390/bioengineering11090928 - 16 Sep 2024

Cited by 5 | Viewed by 1371

Abstract

Sequential drilling is a common practice in dental implant surgery aimed at minimizing thermal damage to bone. This study evaluates the thermal effects of sequential drilling and assesses modifications to drilling protocols to manage heat generation. We utilized a custom drill press and [...] Read more.

Sequential drilling is a common practice in dental implant surgery aimed at minimizing thermal damage to bone. This study evaluates the thermal effects of sequential drilling and assesses modifications to drilling protocols to manage heat generation. We utilized a custom drill press and artificial bone models to test five drill bits under various protocols, including sequential drilling with different loads, spindle speeds, and peck drilling. Infrared thermography recorded temperature changes during the drilling process, with temperatures monitored at various depths around the osteotomy. The results reveal sequential drilling does not eliminate the thermal damage zone it creates (well over 70 °C). It creates harmful heat to surrounding bone that can spread up to 10 mm from the osteotomy. The first drill used in sequential drilling produces the highest temperatures (over 100 °C), and subsequent drill bits cannot remove the thermal trauma incurred; rather, they add to it. Modifying drill bit design and employing proper drilling techniques, such as reducing drilling RPM and load, can reduce thermal trauma by reducing friction. Inadequate management of heat can lead to prolonged recovery, increased patient discomfort, and potential long-term complications such as impaired bone-to-implant integration and chronic conditions like peri-implantitis. Ensuring healthy bone conditions is critical for successful implant outcomes. Full article

(This article belongs to the Special Issue Advanced Assessment of Medical Devices)

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5 pages, 154 KiB

Open AccessEditor’s ChoiceEditorial

Advanced Engineering Technology in Orthopedic Research

by Rongshan Cheng, Huizhi Wang and Cheng-Kung Cheng

Bioengineering 2024, 11(9), 925; https://doi.org/10.3390/bioengineering11090925 - 15 Sep 2024

Cited by 1 | Viewed by 1162

Abstract

Musculoskeletal injuries are increasing in conjunction with the aging of populations and the rising frequency of exercise [...] Full article

(This article belongs to the Special Issue Advanced Engineering Technology in Orthopaedic Research)

18 pages, 1415 KiB

Open AccessEditor’s ChoiceArticle

Optimizing Fall Risk Diagnosis in Older Adults Using a Bayesian Classifier and Simulated Annealing

by Enrique Hernandez-Laredo, Ángel Gabriel Estévez-Pedraza, Laura Mercedes Santiago-Fuentes and Lorena Parra-Rodríguez

Bioengineering 2024, 11(9), 908; https://doi.org/10.3390/bioengineering11090908 - 11 Sep 2024

Cited by 1 | Viewed by 1464

Abstract

The aim of this study was to improve the diagnostic ability of fall risk classifiers using a Bayesian approach and the Simulated Annealing (SA) algorithm. A total of 47 features from 181 records (40 Center of Pressure (CoP) indices and 7 patient descriptive [...] Read more.

The aim of this study was to improve the diagnostic ability of fall risk classifiers using a Bayesian approach and the Simulated Annealing (SA) algorithm. A total of 47 features from 181 records (40 Center of Pressure (CoP) indices and 7 patient descriptive variables) were analyzed. The wrapper method of feature selection using the SA algorithm was applied to optimize the cost function based on the difference of the mean minus the standard deviation of the Area Under the Curve (AUC) of the fall risk classifiers across multiple dimensions. A stratified 60–20–20% hold-out method was used for train, test, and validation sets, respectively. The results showed that although the highest performance was observed with 31 features (0.815 ± 0.110), lower variability and higher explainability were achieved with only 15 features (0.780 ± 0.055). These findings suggest that the SA algorithm is a valuable tool for feature selection for acceptable fall risk diagnosis. This method offers an alternative or complementary resource in situations where clinical tools are difficult to apply. Full article

(This article belongs to the Special Issue Musculoskeletal Disorders and Diseases: Biomechanical Modeling in Sport, Health, Rehabilitation and Ergonomics)

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18 pages, 7246 KiB

Open AccessEditor’s ChoiceArticle

Comparative Study of Alternative Methods for Measuring Leg Length Discrepancy after Robot-Assisted Total Hip Arthroplasty

by Hamad Nazmy, Giovanni Solitro, Benjamin Domb and Farid Amirouche

Bioengineering 2024, 11(8), 853; https://doi.org/10.3390/bioengineering11080853 - 21 Aug 2024

Cited by 1 | Viewed by 1636

Abstract

Background: Our study addresses the lack of consensus on measuring leg length discrepancy (LLD) after total hip arthroplasty (THA). We will assess the inter-observer variability and correlation between the five most commonly used LLD methods and investigate the use of trigonometric principles in [...] Read more.

Background: Our study addresses the lack of consensus on measuring leg length discrepancy (LLD) after total hip arthroplasty (THA). We will assess the inter-observer variability and correlation between the five most commonly used LLD methods and investigate the use of trigonometric principles in overcoming the limitations of current techniques. Methods: LLD was measured on postoperative AP pelvic radiographs using five conventional methods. CT images created a 3D computer model of the pelvis and femur. The resulting models were projected onto a 2D, used to measure LLD by the five methods. The measurements were evaluated via Taguchi analysis, a statistical method identifying the process’s most influential factors. The approach was used to assess the new trigonometric method. Results: Conventional methods demonstrated poor correlation. Methods referenced to the centers of the femoral heads were insensitive to LLD originating outside the acetabular cup. Methods referencing either the inter-ischial line or the inter-obturator foramina to the lesser trochanter were sensitive to acetabular and femoral components. Trigonometry-based measurements showed a higher correlation. Conclusions: Our results underscore clinicians’ need to specify the methods used to assess LLD. Applying trigonometric principles was shown to be accurate and reliable, but it was contingent on proper radiographic alignment. Full article

(This article belongs to the Special Issue Fundamentals of Orthopaedic Biomechanics: Implants, AI, and Innovation in Surgery)

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20 pages, 4364 KiB

Open AccessEditor’s ChoiceArticle

3D Quantitative-Amplified Magnetic Resonance Imaging (3D q-aMRI)

by Itamar Terem, Kyan Younes, Nan Wang, Paul Condron, Javid Abderezaei, Haribalan Kumar, Hillary Vossler, Eryn Kwon, Mehmet Kurt, Elizabeth Mormino, Samantha Holdsworth and Kawin Setsompop

Bioengineering 2024, 11(8), 851; https://doi.org/10.3390/bioengineering11080851 - 20 Aug 2024

Cited by 5 | Viewed by 2630

Abstract

Amplified MRI (aMRI) is a promising new technique that can visualize pulsatile brain tissue motion by amplifying sub-voxel motion in cine MRI data, but it lacks the ability to quantify the sub-voxel motion field in physical units. Here, we introduce a novel post-processing [...] Read more.

Amplified MRI (aMRI) is a promising new technique that can visualize pulsatile brain tissue motion by amplifying sub-voxel motion in cine MRI data, but it lacks the ability to quantify the sub-voxel motion field in physical units. Here, we introduce a novel post-processing algorithm called 3D quantitative amplified MRI (3D q-aMRI). This algorithm enables the visualization and quantification of pulsatile brain motion. 3D q-aMRI was validated and optimized on a 3D digital phantom and was applied in vivo on healthy volunteers for its ability to accurately measure brain parenchyma and CSF voxel displacement. Simulation results show that 3D q-aMRI can accurately quantify sub-voxel motions in the order of 0.01 of a voxel size. The algorithm hyperparameters were optimized and tested on in vivo data. The repeatability and reproducibility of 3D q-aMRI were shown on six healthy volunteers. The voxel displacement field extracted by 3D q-aMRI is highly correlated with the displacement measurements estimated by phase contrast (PC) MRI. In addition, the voxel displacement profile through the cerebral aqueduct resembled the CSF flow profile reported in previous literature. Differences in brain motion was observed in patients with dementia compared with age-matched healthy controls. In summary, 3D q-aMRI is a promising new technique that can both visualize and quantify pulsatile brain motion. Its ability to accurately quantify sub-voxel motion in physical units holds potential for the assessment of pulsatile brain motion as well as the indirect assessment of CSF homeostasis. While further research is warranted, 3D q-aMRI may provide important diagnostic information for neurological disorders such as Alzheimer’s disease. Full article

(This article belongs to the Special Issue Novel MRI Techniques and Biomedical Image Processing)

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14 pages, 3003 KiB

Open AccessEditor’s ChoiceArticle

Stable and Thin-Polymer-Based Modification of Neurovascular Stents with 2-Methacryloyloxyethyl Phosphorylcholine Polymer for Antithrombogenicity

by Naoki Inuzuka, Yasuhiro Shobayashi, Satoshi Tateshima, Yuya Sato, Yoshio Ohba, Kazuhiko Ishihara and Yuji Teramura

Bioengineering 2024, 11(8), 833; https://doi.org/10.3390/bioengineering11080833 - 15 Aug 2024

Cited by 3 | Viewed by 2447

Abstract

The advent of intracranial stents has revolutionized the endovascular treatment of cerebral aneurysms. The utilization of stents has rendered numerous cerebral aneurysm amenable to endovascular treatment, thereby obviating the need for otherwise invasive open surgical options. Stent placement has become a mainstream approach [...] Read more.

The advent of intracranial stents has revolutionized the endovascular treatment of cerebral aneurysms. The utilization of stents has rendered numerous cerebral aneurysm amenable to endovascular treatment, thereby obviating the need for otherwise invasive open surgical options. Stent placement has become a mainstream approach because of its safety and efficacy. However, further improvements are required for clinically approved devices to avoid the frequent occurrence of thrombotic complications. Therefore, controlling the thrombotic complications associated with the use of devices is of significant importance. Our group has developed a unique stent coated with a 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer. In this study, the surface characteristics of the polymer coating were verified using X-ray photoelectron spectroscopy and atomic force microscopy. Subsequently, the antithrombotic properties of the coating were evaluated by measuring platelet count and thrombin–antithrombin complex levels of whole human blood after 3 h of incubation in a Chandler loop model. Scanning electron microscopy was utilized to examine thrombus formation on the stent surface. We observed that MPC polymer-coated stents significantly reduced thrombus formation as compared to bare stents and several clinically approved devices. Finally, the coated stents were further analyzed by implanting them in the internal thoracic arteries of pigs. Angiographic imaging and histopathological examinations that were performed one week after implantation revealed that the vascular lumen was well maintained and coated stents were integrated within the vascular endothelium without inducing adverse effects. Thus, we demonstrated the efficacy of MPC polymer coating as a viable strategy for avoiding the thrombotic risks associated with neurovascular stents. Full article

(This article belongs to the Special Issue Advanced Biomaterials, Coatings, and Techniques: Applications in Medicine)

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16 pages, 5882 KiB

Open AccessEditor’s ChoiceArticle

Perlecan: An Islet Basement Membrane Protein with Protective Anti-Inflammatory Characteristics

by Daniel Brandhorst, Heide Brandhorst, Samuel Acreman and Paul R. V. Johnson

Bioengineering 2024, 11(8), 828; https://doi.org/10.3390/bioengineering11080828 - 13 Aug 2024

Cited by 1 | Viewed by 1340

Abstract

Throughout the isolation process, human islets are subjected to destruction of the islet basement membrane (BM) and reduced oxygen supply. Reconstruction of the BM represents an option to improve islet function and survival post-transplant and may particularly be relevant for islet encapsulation devices [...] Read more.

Throughout the isolation process, human islets are subjected to destruction of the islet basement membrane (BM) and reduced oxygen supply. Reconstruction of the BM represents an option to improve islet function and survival post-transplant and may particularly be relevant for islet encapsulation devices and scaffolds. In the present study, we assessed whether Perlecan, used alone or combined with the BM proteins (BMPs) Collagen-IV and Laminin-521, has the ability to protect isolated human islets from hypoxia-induced damage. Islets isolated from the pancreas of seven different organ donors were cultured for 4–5 days at 2% oxygen in plain CMRL (sham-treated controls) or in CMRL supplemented with BMPs used either alone or in combination. Postculture, islets were characterized regarding survival, in vitro function and production of chemokines and reactive oxygen species (ROS). Individually added BMPs significantly doubled islet survival and increased in vitro function. Combining BMPs did not provide a synergistic effect. Among the tested BMPs, Perlecan demonstrated the significantly strongest inhibitory effect on chemokine and ROS production when compared with sham-treatment (p < 0.001). Perlecan may be useful to improve islet survival prior to and after transplantation. Its anti-inflammatory potency should be considered to optimise encapsulation and scaffolds to protect isolated human islets post-transplant. Full article

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

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16 pages, 3418 KiB

Open AccessEditor’s ChoiceArticle

Biomechanical Study of Symmetric Bending and Lifting Behavior in Weightlifter with Lumbar L4-L5 Disc Herniation and Physiological Straightening Using Finite Element Simulation

by Caiting Zhang, Yang Song, Qiaolin Zhang, Ee-Chon Teo and Wei Liu

Bioengineering 2024, 11(8), 825; https://doi.org/10.3390/bioengineering11080825 - 12 Aug 2024

Cited by 1 | Viewed by 1987

Abstract

Background: Physiological curvature changes of the lumbar spine and disc herniation can cause abnormal biomechanical responses of the lumbar spine. Finite element (FE) studies on special weightlifter models are limited, yet understanding stress in damaged lumbar spines is crucial for preventing and rehabilitating [...] Read more.

Background: Physiological curvature changes of the lumbar spine and disc herniation can cause abnormal biomechanical responses of the lumbar spine. Finite element (FE) studies on special weightlifter models are limited, yet understanding stress in damaged lumbar spines is crucial for preventing and rehabilitating lumbar diseases. This study analyzes the biomechanical responses of a weightlifter with lumbar straightening and L4-L5 disc herniation during symmetric bending and lifting to optimize training and rehabilitation. Methods: Based on the weightlifter’s computed tomography (CT) data, an FE lumbar spine model (L1-L5) was established. The model included normal intervertebral discs (IVDs), vertebral endplates, ligaments, and a degenerated L4-L5 disc. The bending angle was set to 45°, and weights of 15 kg, 20 kg, and 25 kg were used. The flexion moment for lifting these weights was theoretically calculated. The model was tilted at 45° in Abaqus 2021 (Dassault Systèmes Simulia Corp., Johnston, RI, USA), with L5 constrained in all six degrees of freedom. A vertical load equivalent to the weightlifter’s body mass and the calculated flexion moments were applied to L1 to simulate the weightlifter’s bending and lifting behavior. Biomechanical responses within the lumbar spine were then analyzed. Results: The displacement and range of motion (ROM) of the lumbar spine were similar under all three loading conditions. The flexion degree increased with the load, while extension remained unchanged. Right-side movement and bending showed minimal change, with slightly more right rotation. Stress distribution trends were similar across loads, primarily concentrated in the vertebral body, increasing with load. Maximum stress occurred at the anterior inferior margin of L5, with significant stress at the posterior joints, ligaments, and spinous processes. The posterior L5 and margins of L1 and L5 experienced high stress. The degenerated L4-L5 IVD showed stress concentration on its edges, with significant stress also on L3-L4 IVD. Stress distribution in the lumbar spine was uneven. Conclusions: Our findings highlight the impact on spinal biomechanics and suggest reducing anisotropic loading and being cautious of loaded flexion positions affecting posterior joints, IVDs, and vertebrae. This study offers valuable insights for the rehabilitation and treatment of similar patients. Full article

(This article belongs to the Special Issue Advances in Trauma and Injury Biomechanics)

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25 pages, 1522 KiB

Open AccessEditor’s ChoiceReview

Toward Fully Automated Personalized Orthopedic Treatments: Innovations and Interdisciplinary Gaps

by Yunhua Luo

Bioengineering 2024, 11(8), 817; https://doi.org/10.3390/bioengineering11080817 - 12 Aug 2024

Cited by 3 | Viewed by 2098

Abstract

Personalized orthopedic devices are increasingly favored for their potential to enhance long-term treatment success. Despite significant advancements across various disciplines, the seamless integration and full automation of personalized orthopedic treatments remain elusive. This paper identifies key interdisciplinary gaps in integrating and automating advanced [...] Read more.

Personalized orthopedic devices are increasingly favored for their potential to enhance long-term treatment success. Despite significant advancements across various disciplines, the seamless integration and full automation of personalized orthopedic treatments remain elusive. This paper identifies key interdisciplinary gaps in integrating and automating advanced technologies for personalized orthopedic treatment. It begins by outlining the standard clinical practices in orthopedic treatments and the extent of personalization achievable. The paper then explores recent innovations in artificial intelligence, biomaterials, genomic and proteomic analyses, lab-on-a-chip, medical imaging, image-based biomechanical finite element modeling, biomimicry, 3D printing and bioprinting, and implantable sensors, emphasizing their contributions to personalized treatments. Tentative strategies or solutions are proposed to address the interdisciplinary gaps by utilizing innovative technologies. The key findings highlight the need for the non-invasive quantitative assessment of bone quality, patient-specific biocompatibility, and device designs that address individual biological and mechanical conditions. This comprehensive review underscores the transformative potential of these technologies and the importance of multidisciplinary collaboration to integrate and automate them into a cohesive, intelligent system for personalized orthopedic treatments. Full article

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

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4 pages, 179 KiB

Open AccessEditor’s ChoiceEditorial

Advancements in Biomedical and Bioengineering Technologies in Sports Monitoring and Healthcare

by Yaodong Gu and Justin Fernandez

Bioengineering 2024, 11(8), 816; https://doi.org/10.3390/bioengineering11080816 - 12 Aug 2024

Viewed by 1864

Abstract

The intersection of biomedical and bioengineering technologies with sports monitoring and healthcare has recently emerged as a key area of innovation and research [...] Full article

(This article belongs to the Special Issue Biomedical and Bioengineering Technology: Current Applications in Sports Monitoring and Health Care)

17 pages, 5078 KiB

Open AccessEditor’s ChoiceReview

Advancing Cordyceps militaris Industry: Gene Manipulation and Sustainable Biotechnological Strategies

by Yan Hu, Yijian Wu, Jiayi Song, Maomao Ma, Yunzhu Xiao and Bin Zeng

Bioengineering 2024, 11(8), 783; https://doi.org/10.3390/bioengineering11080783 - 2 Aug 2024

Cited by 1 | Viewed by 3664

Abstract

Cordyceps militaris is considered to be of great medicinal potential due to its remarkable pharmacological effects, safety, and edible characteristics. With the completion of the genome sequence and the advancement of efficient gene-editing technologies, coupled with the identification of gene functions in Cordyceps [...] Read more.

Cordyceps militaris is considered to be of great medicinal potential due to its remarkable pharmacological effects, safety, and edible characteristics. With the completion of the genome sequence and the advancement of efficient gene-editing technologies, coupled with the identification of gene functions in Cordyceps militaris, this fungus is poised to emerge as an outstanding strain for medicinal engineering applications. This review focuses on the development and application of genomic editing techniques, including Agrobacterium tumefaciens-mediated transformation (ATMT), PEG-mediated protoplast transformation (PMT), and CRISPR/Cas9. Through the application of these techniques, researchers can engineer the biosynthetic pathways of valuable secondary metabolites to boost yields; such metabolites include cordycepin, polysaccharides, and ergothioneine. Furthermore, by identifying and modifying genes that influence the growth, disease resistance, and tolerance to environmental stress in Cordyceps militaris, it is possible to stimulate growth, enhance desirable traits, and increase resilience to unfavorable conditions. Finally, the green sustainable industrial development of C. militaris using agricultural waste to produce high-value-added products and the future research directions of C. militaris were discussed. This review will provide future directions for the large-scale production of bioactive ingredients, molecular breeding, and sustainable development of C. militaris. Full article

(This article belongs to the Section Biochemical Engineering)

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29 pages, 1873 KiB

Open AccessEditor’s ChoiceReview

Biohacking Nerve Repair: Novel Biomaterials, Local Drug Delivery, Electrical Stimulation, and Allografts to Aid Surgical Repair

by Jordan R. Crabtree, Chilando M. Mulenga, Khoa Tran, Konstantin Feinberg, J. Paul Santerre and Gregory H. Borschel

Bioengineering 2024, 11(8), 776; https://doi.org/10.3390/bioengineering11080776 - 31 Jul 2024

Cited by 6 | Viewed by 2854

Abstract

The regenerative capacity of the peripheral nervous system is limited, and peripheral nerve injuries often result in incomplete healing and poor outcomes even after repair. Transection injuries that induce a nerve gap necessitate microsurgical intervention; however, even the current gold standard of repair, [...] Read more.

The regenerative capacity of the peripheral nervous system is limited, and peripheral nerve injuries often result in incomplete healing and poor outcomes even after repair. Transection injuries that induce a nerve gap necessitate microsurgical intervention; however, even the current gold standard of repair, autologous nerve graft, frequently results in poor functional recovery. Several interventions have been developed to augment the surgical repair of peripheral nerves, and the application of functional biomaterials, local delivery of bioactive substances, electrical stimulation, and allografts are among the most promising approaches to enhance innate healing across a nerve gap. Biocompatible polymers with optimized degradation rates, topographic features, and other functions provided by their composition have been incorporated into novel nerve conduits (NCs). Many of these allow for the delivery of drugs, neurotrophic factors, and whole cells locally to nerve repair sites, mitigating adverse effects that limit their systemic use. The electrical stimulation of repaired nerves in the perioperative period has shown benefits to healing and recovery in human trials, and novel biomaterials to enhance these effects show promise in preclinical models. The use of acellular nerve allografts (ANAs) circumvents the morbidity of donor nerve harvest necessitated by the use of autografts, and improvements in tissue-processing techniques may allow for more readily available and cost-effective options. Each of these interventions aid in neural regeneration after repair when applied independently, and their differing forms, benefits, and methods of application present ample opportunity for synergistic effects when applied in combination. Full article

(This article belongs to the Special Issue Bioengineering Strategies for Nerve Repair)

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27 pages, 7176 KiB

Open AccessEditor’s ChoiceArticle

Helmet Radio Frequency Phased Array Applicators Enhance Thermal Magnetic Resonance of Brain Tumors

by Faezeh Rahimi, Bilguun Nurzed, Thomas W. Eigentler, Mostafa Berangi, Eva Oberacker, Andre Kuehne, Pirus Ghadjar, Jason M. Millward, Rolf Schuhmann and Thoralf Niendorf

Bioengineering 2024, 11(7), 733; https://doi.org/10.3390/bioengineering11070733 - 19 Jul 2024

Cited by 1 | Viewed by 2032

Abstract

Thermal Magnetic Resonance (ThermalMR) integrates Magnetic Resonance Imaging (MRI) diagnostics and targeted radio-frequency (RF) heating in a single theranostic device. The requirements for MRI (magnetic field) and targeted RF heating (electric field) govern the design of ThermalMR applicators. We hypothesize that helmet RF [...] Read more.

Thermal Magnetic Resonance (ThermalMR) integrates Magnetic Resonance Imaging (MRI) diagnostics and targeted radio-frequency (RF) heating in a single theranostic device. The requirements for MRI (magnetic field) and targeted RF heating (electric field) govern the design of ThermalMR applicators. We hypothesize that helmet RF applicators (HPA) improve the efficacy of ThermalMR of brain tumors versus an annular phased RF array (APA). An HPA was designed using eight broadband self-grounded bow-tie (SGBT) antennae plus two SGBTs placed on top of the head. An APA of 10 equally spaced SGBTs was used as a reference. Electromagnetic field (EMF) simulations were performed for a test object (phantom) and a human head model. For a clinical scenario, the head model was modified with a tumor volume obtained from a patient with glioblastoma multiforme. To assess performance, we introduced multi-target evaluation (MTE) to ensure whole-brain slice accessibility. We implemented time multiplexed vector field shaping to optimize RF excitation. Our EMF and temperature simulations demonstrate that the HPA improves performance criteria critical to MRI and enhances targeted RF and temperature focusing versus the APA. Our findings are a foundation for the experimental implementation and application of a HPA en route to ThermalMR of brain tumors. Full article

(This article belongs to the Special Issue Advances in Thermal Therapy)

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13 pages, 4398 KiB

Open AccessEditor’s ChoiceArticle

Fabrication and Evaluation of PCL/PLGA/β-TCP Spiral-Structured Scaffolds for Bone Tissue Engineering

by Weiwei Wang, Xiaqing Zhou, Haoyu Wang, Gan Zhou and Xiaojun Yu

Bioengineering 2024, 11(7), 732; https://doi.org/10.3390/bioengineering11070732 - 19 Jul 2024

Cited by 2 | Viewed by 2245

Abstract

Natural bone is a complex material that has been carefully designed. To prepare a successful bone substitute, two challenging conditions need to be met: biocompatible and bioactive materials for cell proliferation and differentiation, and appropriate mechanical stability after implantation. Therefore, a hybrid Poly [...] Read more.

Natural bone is a complex material that has been carefully designed. To prepare a successful bone substitute, two challenging conditions need to be met: biocompatible and bioactive materials for cell proliferation and differentiation, and appropriate mechanical stability after implantation. Therefore, a hybrid Poly ε-caprolactone/Poly(lactic-co-glycolide)/β-tricalcium phosphate (PCL/PLGA/β-TCP) scaffold has been introduced as a suitable composition that satisfies the above two conditions. The blended PCL and PLGA can improve the scaffold’s mechanical properties and biocompatibility compared to single PCL or PLGA scaffolds. In addition, the incorporated β-TCP increases the mechanical strength and osteogenic potential of PCL/PLGA scaffolds, while the polymer improves the mechanical stability of ceramic scaffolds. The PCL/PLGA/β-TCP scaffold is designed using spiral structures to provide a much better transport system through the gaps between spiral walls than conventional cylindrical scaffolds. Human fetal osteoblasts (hFOBs) were cultured on spiral PCL/PLGA/β-TCP (PPBS), cylindrical PCL/PLGA/β-TCP (PPBC), and cylindrical PCL scaffolds for a total of 28 days. The cell proliferation, viability, and osteogenic differentiation capabilities were analyzed. Compared with PCL and PPBC scaffolds, the PPBS scaffold exhibits great biocompatibility and potential to stimulate cell proliferation and differentiation and, therefore, can serve as a bone substitute for bone tissue regeneration. Full article

(This article belongs to the Special Issue Biomaterial Scaffolds for Tissue Engineering)

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22 pages, 4120 KiB

Open AccessEditor’s ChoiceArticle

Three-Dimensionally Printed Agarose Micromold Supports Scaffold-Free Mouse Ex Vivo Follicle Growth, Ovulation, and Luteinization

by Emily J. Zaniker, Prianka H. Hashim, Samuel Gauthier, James A. Ankrum, Hannes Campo and Francesca E. Duncan

Bioengineering 2024, 11(7), 719; https://doi.org/10.3390/bioengineering11070719 - 15 Jul 2024

Cited by 2 | Viewed by 4979

Abstract

Ex vivo follicle growth is an essential tool, enabling interrogation of folliculogenesis, ovulation, and luteinization. Though significant advancements have been made, existing follicle culture strategies can be technically challenging and laborious. In this study, we advanced the field through development of a custom [...] Read more.

Ex vivo follicle growth is an essential tool, enabling interrogation of folliculogenesis, ovulation, and luteinization. Though significant advancements have been made, existing follicle culture strategies can be technically challenging and laborious. In this study, we advanced the field through development of a custom agarose micromold, which enables scaffold-free follicle culture. We established an accessible and economical manufacturing method using 3D printing and silicone molding that generates biocompatible hydrogel molds without the risk of cytotoxicity from leachates. Each mold supports simultaneous culture of multiple multilayer secondary follicles in a single focal plane, allowing for constant timelapse monitoring and automated analysis. Mouse follicles cultured using this novel system exhibit significantly improved growth and ovulation outcomes with comparable survival, oocyte maturation, and hormone production profiles as established three-dimensional encapsulated in vitro follicle growth (eIVFG) systems. Additionally, follicles recapitulated aspects of in vivo ovulation physiology with respect to their architecture and spatial polarization, which has not been observed in eIVFG systems. This system offers simplicity, scalability, integration with morphokinetic analyses of follicle growth and ovulation, and compatibility with existing microphysiological platforms. This culture strategy has implications for fundamental follicle biology, fertility preservation strategies, reproductive toxicology, and contraceptive drug discovery. Full article

(This article belongs to the Special Issue Bioengineering Technologies to Advance Reproductive Health)

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10 pages, 225 KiB

Open AccessEditor’s ChoiceCommentary

Bridging the Gap: Integrating 3D Bioprinting and Microfluidics for Advanced Multi-Organ Models in Biomedical Research

by Marco De Spirito, Valentina Palmieri, Giordano Perini and Massimiliano Papi

Bioengineering 2024, 11(7), 664; https://doi.org/10.3390/bioengineering11070664 - 28 Jun 2024

Cited by 8 | Viewed by 2228

Abstract

Recent advancements in 3D bioprinting and microfluidic lab-on-chip systems offer promising solutions to the limitations of traditional animal models in biomedical research. Three-dimensional bioprinting enables the creation of complex, patient-specific tissue models that mimic human physiology more accurately than animal models. These 3D [...] Read more.

Recent advancements in 3D bioprinting and microfluidic lab-on-chip systems offer promising solutions to the limitations of traditional animal models in biomedical research. Three-dimensional bioprinting enables the creation of complex, patient-specific tissue models that mimic human physiology more accurately than animal models. These 3D bioprinted tissues, when integrated with microfluidic systems, can replicate the dynamic environment of the human body, allowing for the development of multi-organ models. This integration facilitates more precise drug screening and personalized therapy development by simulating interactions between different organ systems. Such innovations not only improve predictive accuracy but also address ethical concerns associated with animal testing, aligning with the three Rs principle. Future directions include enhancing bioprinting resolution, developing advanced bioinks, and incorporating AI for optimized system design. These technologies hold the potential to revolutionize drug development, regenerative medicine, and disease modeling, leading to more effective, personalized, and humane treatments. Full article

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

20 pages, 3488 KiB

Open AccessEditor’s ChoiceReview

Digital Twins for Healthcare Using Wearables

by Zachary Johnson and Manob Jyoti Saikia

Bioengineering 2024, 11(6), 606; https://doi.org/10.3390/bioengineering11060606 - 13 Jun 2024

Cited by 4 | Viewed by 4728

Abstract

Digital twins are a relatively new form of digital modeling that has been gaining popularity in recent years. This is in large part due to their ability to update in real time to their physical counterparts and connect across multiple devices. As a [...] Read more.

Digital twins are a relatively new form of digital modeling that has been gaining popularity in recent years. This is in large part due to their ability to update in real time to their physical counterparts and connect across multiple devices. As a result, much interest has been directed towards using digital twins in the healthcare industry. Recent advancements in smart wearable technologies have allowed for the utilization of human digital twins in healthcare. Human digital twins can be generated using biometric data from the patient gathered from wearables. These data can then be used to enhance patient care through a variety of means, such as simulated clinical trials, disease prediction, and monitoring treatment progression remotely. This revolutionary method of patient care is still in its infancy, and as such, there is limited research on using wearables to generate human digital twins for healthcare applications. This paper reviews the literature pertaining to human digital twins, including methods, applications, and challenges. The paper also presents a conceptual method for creating human body digital twins using wearable sensors. Full article

(This article belongs to the Special Issue Wearable Sensors and Measurement Systems for Human Physiology Monitoring)

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13 pages, 2959 KiB

Open AccessEditor’s ChoiceReview

Alexander Friedenstein, Mesenchymal Stem Cells, Shifting Paradigms and Euphemisms

by Donald G. Phinney

Bioengineering 2024, 11(6), 534; https://doi.org/10.3390/bioengineering11060534 - 23 May 2024

Cited by 1 | Viewed by 2069

Abstract

Six decades ago, Friedenstein and coworkers published a series of seminal papers identifying a cell population in bone marrow with osteogenic potential, now referred to as mesenchymal stem cells (MSCs). This work was also instrumental in establishing the identity of hematopoietic stem cell [...] Read more.

Six decades ago, Friedenstein and coworkers published a series of seminal papers identifying a cell population in bone marrow with osteogenic potential, now referred to as mesenchymal stem cells (MSCs). This work was also instrumental in establishing the identity of hematopoietic stem cell and the identification of skeletal stem/progenitor cell (SSPC) populations in various skeletal compartments. In recognition of the centenary year of Friedenstein’s birth, I review key aspects of his work and discuss the evolving concept of the MSC and its various euphemisms indorsed by changing paradigms in the field. I also discuss the recent emphasis on MSC stromal quality attributes and how emerging data demonstrating a mechanistic link between stromal and stem/progenitor functions bring renewed relevance to Friedenstein’s contributions and much needed unity to the field. Full article

(This article belongs to the Special Issue A Tribute to Professor Alexander Friedenstein and His Outstanding Achievements in the Area of Stromal Stem Cells)

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16 pages, 1572 KiB

Open AccessEditor’s ChoiceReview

Where Does Auto-Segmentation for Brain Metastases Radiosurgery Stand Today?

by Matthew Kim, Jen-Yeu Wang, Weiguo Lu, Hao Jiang, Strahinja Stojadinovic, Zabi Wardak, Tu Dan, Robert Timmerman, Lei Wang, Cynthia Chuang, Gregory Szalkowski, Lianli Liu, Erqi Pollom, Elham Rahimy, Scott Soltys, Mingli Chen and Xuejun Gu

Bioengineering 2024, 11(5), 454; https://doi.org/10.3390/bioengineering11050454 - 3 May 2024

Cited by 3 | Viewed by 2226

Abstract

Detection and segmentation of brain metastases (BMs) play a pivotal role in diagnosis, treatment planning, and follow-up evaluations for effective BM management. Given the rising prevalence of BM cases and its predominantly multiple onsets, automated segmentation is becoming necessary in stereotactic radiosurgery. It [...] Read more.

Detection and segmentation of brain metastases (BMs) play a pivotal role in diagnosis, treatment planning, and follow-up evaluations for effective BM management. Given the rising prevalence of BM cases and its predominantly multiple onsets, automated segmentation is becoming necessary in stereotactic radiosurgery. It not only alleviates the clinician’s manual workload and improves clinical workflow efficiency but also ensures treatment safety, ultimately improving patient care. Recent strides in machine learning, particularly in deep learning (DL), have revolutionized medical image segmentation, achieving state-of-the-art results. This review aims to analyze auto-segmentation strategies, characterize the utilized data, and assess the performance of cutting-edge BM segmentation methodologies. Additionally, we delve into the challenges confronting BM segmentation and share insights gleaned from our algorithmic and clinical implementation experiences. Full article

(This article belongs to the Special Issue Artificial Intelligence in Biomedical Diagnosis and Prognosis)

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14 pages, 2236 KiB

Open AccessEditor’s ChoiceArticle

Polyhydroxyalkanoate Copolymer Production by Recombinant Ralstonia eutropha Strain 1F2 from Fructose or Carbon Dioxide as Sole Carbon Source

by Chih-Ting Wang, Ramamoorthi M Sivashankari, Yuki Miyahara and Takeharu Tsuge

Bioengineering 2024, 11(5), 455; https://doi.org/10.3390/bioengineering11050455 - 2 May 2024

Cited by 2 | Viewed by 2580

Abstract

Ralstonia eutropha strain H16 is a chemoautotrophic bacterium that oxidizes hydrogen and accumulates poly[(R)-3-hydroxybutyrate] [P(3HB)], a prominent polyhydroxyalkanoate (PHA), within its cell. R. eutropha utilizes fructose or CO₂ as its sole carbon source for this process. A PHA-negative mutant of [...] Read more.

Ralstonia eutropha strain H16 is a chemoautotrophic bacterium that oxidizes hydrogen and accumulates poly[(R)-3-hydroxybutyrate] [P(3HB)], a prominent polyhydroxyalkanoate (PHA), within its cell. R. eutropha utilizes fructose or CO₂ as its sole carbon source for this process. A PHA-negative mutant of strain H16, known as R. eutropha strain PHB⁻4, cannot produce PHA. Strain 1F2, derived from strain PHB⁻4, is a leucine analog-resistant mutant. Remarkably, the recombinant 1F2 strain exhibits the capacity to synthesize 3HB-based PHA copolymers containing 3-hydroxyvalerate (3HV) and 3-hydroxy-4-methyvalerate (3H4MV) comonomer units from fructose or CO_2. This ability is conferred by the expression of a broad substrate-specific PHA synthase and tolerance to feedback inhibition of branched amino acids. However, the total amount of comonomer units incorporated into PHA was up to around 5 mol%. In this study, strain 1F2 underwent genetic engineering to augment the comonomer supply incorporated into PHA. This enhancement involved several modifications, including the additional expression of the broad substrate-specific 3-ketothiolase gene (bktB), the heterologous expression of the 2-ketoacid decarboxylase gene (kivd), and the phenylacetaldehyde dehydrogenase gene (padA). Furthermore, the genome of strain 1F2 was altered through the deletion of the 3-hydroxyacyl-CoA dehydrogenase gene (hbdH). The introduction of bktB-kivd-padA resulted in increased 3HV incorporation, reaching 13.9 mol% from fructose and 6.4 mol% from CO₂. Additionally, the hbdH deletion resulted in the production of PHA copolymers containing (S)-3-hydroxy-2-methylpropionate (3H2MP). Interestingly, hbdH deletion increased the weight-average molecular weight of the PHA to over 3.0 × 10⁶ on fructose. Thus, it demonstrates the positive effects of hbdH deletion on the copolymer composition and molecular weight of PHA. Full article

(This article belongs to the Special Issue Advances in Polyhydroxyalkanoate (PHA) Production, 4th Edition)

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16 pages, 3345 KiB

Open AccessEditor’s ChoiceArticle

Predictive Refined Computational Modeling of ACL Tear Injury Patterns

by Mirit Sharabi, Raz Agron, Amir Dolev, Rami Haj-Ali and Mustafa Yassin

Bioengineering 2024, 11(5), 413; https://doi.org/10.3390/bioengineering11050413 - 23 Apr 2024

Cited by 1 | Viewed by 2400

Abstract

Anterior cruciate ligament (ACL) ruptures are prevalent knee injuries, with approximately 200,000 ruptures annually, and treatment costs exceed USD two billion in the United States alone. Typically, the initial detection of ACL tears and anterior tibial laxity (ATL) involves manual assessments like the [...] Read more.

Anterior cruciate ligament (ACL) ruptures are prevalent knee injuries, with approximately 200,000 ruptures annually, and treatment costs exceed USD two billion in the United States alone. Typically, the initial detection of ACL tears and anterior tibial laxity (ATL) involves manual assessments like the Lachman test, which examines anterior knee laxity. Partial ACL tears can go unnoticed if they minimally affect knee laxity; however, they will progress to a complete ACL tear requiring surgical treatment. In this study, a computational finite element model (FEM) of the knee joint was generated to investigate the effect of partial ACL tears under the Lachman test (GNRB^® testing system) boundary conditions. The ACL was modeled as a hyperelastic composite structure with a refined representation of collagen bundles. Five different tear types (I–V), classified by location and size, were modeled to predict the relationship between tear size, location, and anterior tibial translation (ATT). The results demonstrated different levels of ATT that could not be manually detected. Type I tears demonstrated an almost linear increase in ATT, with the growth in tear size ranging from 3.7 mm to 4.2 mm, from 25% to 85%, respectively. Type II partial tears showed a less linear incline in ATT (3.85, 4.1, and 4.75 mm for 25%, 55%, and 85% partial tears, respectively). Types III, IV, and V maintained a nonlinear trend, with ATTs of 3.85 mm, 4.2 mm, and 4.95 mm for Type III, 3.85 mm, 4.25 mm, and 5.1 mm for Type IV, and 3.6 mm, 4.25 mm, and 5.3 mm for Type V, for 25%, 55%, and 85% partial tears, respectively. Therefore, for small tears (25%), knee stability was most affected when the tears were located around the center of the ligament. For moderate tears (55%), the effect on knee stability was the greatest for tears at the proximal half of the ACL. However, severe tears (85%) demonstrated considerable growth in knee instability from the distal to the proximal ends of the tissue, with a substantial increase in knee instability around the insertion sites. The proposed model can enhance the characterization of partial ACL tears, leading to more accurate preliminary diagnoses. It can aid in developing new techniques for repairing partially torn ACLs, potentially preventing more severe injuries. Full article

(This article belongs to the Special Issue Computational Biomechanics, Volume II)

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11 pages, 1891 KiB

Open AccessEditor’s ChoiceArticle

Application of the Single Source—Detector Separation Algorithm in Wearable Neuroimaging Devices: A Step toward Miniaturized Biosensor for Hypoxia Detection

by Thien Nguyen, Soongho Park, Jinho Park, Asma Sodager, Tony George and Amir Gandjbakhche

Bioengineering 2024, 11(4), 385; https://doi.org/10.3390/bioengineering11040385 - 16 Apr 2024

Cited by 1 | Viewed by 2055

Abstract

Most currently available wearable devices to noninvasively detect hypoxia use the spatially resolved spectroscopy (SRS) method to calculate cerebral tissue oxygen saturation (StO₂). This study applies the single source—detector separation (SSDS) algorithm to calculate StO₂. Near-infrared spectroscopy (NIRS) data [...] Read more.

Most currently available wearable devices to noninvasively detect hypoxia use the spatially resolved spectroscopy (SRS) method to calculate cerebral tissue oxygen saturation (StO₂). This study applies the single source—detector separation (SSDS) algorithm to calculate StO₂. Near-infrared spectroscopy (NIRS) data were collected from 26 healthy adult volunteers during a breath-holding task using a wearable NIRS device, which included two source—detector separations (SDSs). These data were used to derive oxyhemoglobin (HbO) change and StO₂. In the group analysis, both HbO change and StO₂ exhibited significant change during a breath-holding task. Specifically, they initially decreased to minimums at around 10 s and then steadily increased to maximums, which were significantly greater than baseline levels, at 25–30 s (p-HbO < 0.001 and p-StO₂ < 0.05). However, at an individual level, the SRS method failed to detect changes in cerebral StO₂ in response to a short breath-holding task. Furthermore, the SSDS algorithm is more robust than the SRS method in quantifying change in cerebral StO₂ in response to a breath-holding task. In conclusion, these findings have demonstrated the potential use of the SSDS algorithm in developing a miniaturized wearable biosensor to monitor cerebral StO₂ and detect cerebral hypoxia. Full article

(This article belongs to the Special Issue Neuroimaging Techniques for Wearable Devices in Bioengineering)

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23 pages, 9165 KiB

Open AccessEditor’s ChoiceArticle

Motion Analysis of the Wrist and Finger Joints in Sport Climbing

by Gabriella Fischer, Micha Schneeberger, Stefan Andreas Petter, Anne-Gita Scheibler, Peter Wolf, Maurizio Calcagni, Andreas Schweizer and Lisa Reissner

Bioengineering 2024, 11(4), 370; https://doi.org/10.3390/bioengineering11040370 - 12 Apr 2024

Cited by 2 | Viewed by 2131

Abstract

Climbing is a fast-growing sport, with one of the most common injuries being a rupture of the finger flexor tendon pulley. The strain on pulleys increases as finger joints flex. However, to our knowledge, no study has conducted a kinematic analysis of climbers’ [...] Read more.

Climbing is a fast-growing sport, with one of the most common injuries being a rupture of the finger flexor tendon pulley. The strain on pulleys increases as finger joints flex. However, to our knowledge, no study has conducted a kinematic analysis of climbers’ fingers. Thus, this study aimed to examine finger kinematics during typical climbing tasks. Eleven elite climbers performed a sequence of four climbing moves, which were recorded by an optical motion capture system. Participants used crimp, half-crimp, and open-hand grips for three trials each, with the fourth condition involving campusing using any grip except crimp. Mean proximal interphalangeal joint (PIP) flexion during the holding phase was 87° (SD 12°), 70° (14°) and 39° (27°) for the crimp, half-crimp and open-hand grip, respectively. Hence, inter-individual PIP flexion ranges overlap between different gripping conditions. Two different movement patterns emerged in the open-hand grip, possibly influenced by the use of the little finger, leading to varying degrees of flexion in the middle and ring fingers. Avoiding little finger usage in the open-hand grip may reduce load during pulley rupture rehabilitation. The implications of PIP joint angle variability on individual pulley injury risk or prevention warrant further investigation. Motion capture proved effective for understanding finger kinematics during climbing and could guide future studies on pulley injury risk factors. Full article

(This article belongs to the Special Issue Biomechanics and Sports Medicine in Sport Climbing, Featuring Selected Contributions Presented at the 6th IRCRA Congress 2023)

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31 pages, 6645 KiB

Open AccessEditor’s ChoiceReview

Recent Advances in Wearable Healthcare Devices: From Material to Application

by Xiao Luo, Handong Tan and Weijia Wen

Bioengineering 2024, 11(4), 358; https://doi.org/10.3390/bioengineering11040358 - 6 Apr 2024

Cited by 10 | Viewed by 13734

Abstract

In recent years, the proliferation of wearable healthcare devices has marked a revolutionary shift in the personal health monitoring and management paradigm. These devices, ranging from fitness trackers to advanced biosensors, have not only made healthcare more accessible, but have also transformed the [...] Read more.

In recent years, the proliferation of wearable healthcare devices has marked a revolutionary shift in the personal health monitoring and management paradigm. These devices, ranging from fitness trackers to advanced biosensors, have not only made healthcare more accessible, but have also transformed the way individuals engage with their health data. By continuously monitoring health signs, from physical-based to biochemical-based such as heart rate and blood glucose levels, wearable technology offers insights into human health, enabling a proactive rather than a reactive approach to healthcare. This shift towards personalized health monitoring empowers individuals with the knowledge and tools to make informed decisions about their lifestyle and medical care, potentially leading to the earlier detection of health issues and more tailored treatment plans. This review presents the fabrication methods of flexible wearable healthcare devices and their applications in medical care. The potential challenges and future prospectives are also discussed. Full article

(This article belongs to the Special Issue Bioanalysis Systems: Materials, Methods, Designs and Applications)

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23 pages, 1871 KiB

Open AccessEditor’s ChoiceReview

Natural Killer Cell Mechanosensing in Solid Tumors

by Suzanne Lightsey and Blanka Sharma

Bioengineering 2024, 11(4), 328; https://doi.org/10.3390/bioengineering11040328 - 28 Mar 2024

Cited by 2 | Viewed by 2851

Abstract

Natural killer (NK) cells, which are an exciting alternative cell source for cancer immunotherapies, must sense and respond to their physical environment to traffic to and eliminate cancer cells. Herein, we review the mechanisms by which NK cells receive mechanical signals and explore [...] Read more.

Natural killer (NK) cells, which are an exciting alternative cell source for cancer immunotherapies, must sense and respond to their physical environment to traffic to and eliminate cancer cells. Herein, we review the mechanisms by which NK cells receive mechanical signals and explore recent key findings regarding the impact of the physical characteristics of solid tumors on NK cell functions. Data suggest that different mechanical stresses present in solid tumors facilitate NK cell functions, especially infiltration and degranulation. Moreover, we review recent engineering advances that can be used to systemically study the role of mechanical forces on NK cell activity. Understanding the mechanisms by which NK cells interpret their environment presents potential targets to enhance NK cell immunotherapies for the treatment of solid tumors. Full article

(This article belongs to the Section Regenerative Engineering)

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