Journal of Functional Biomaterials

28 pages, 6643 KiB

Open AccessEditor’s ChoiceReview

Unveiling Nanoparticles: Recent Approaches in Studying the Internalization Pattern of Iron Oxide Nanoparticles in Mono- and Multicellular Biological Structures

by Teodora Eliana Petcov, Mihai Straticiuc, Decebal Iancu, Dragoș Alexandru Mirea, Roxana Trușcă, Paul Emil Mereuță, Diana Iulia Savu, George Dan Mogoșanu, Laurențiu Mogoantă, Roxana Cristina Popescu, Verena Kopatz and Sorin Ion Jinga

J. Funct. Biomater. 2024, 15(6), 169; https://doi.org/10.3390/jfb15060169 - 19 Jun 2024

Viewed by 892

Abstract

Nanoparticle (NP)-based solutions for oncotherapy promise an improved efficiency of the anticancer response, as well as higher comfort for the patient. The current advancements in cancer treatment based on nanotechnology exploit the ability of these systems to pass biological barriers to target the [...] Read more.

Nanoparticle (NP)-based solutions for oncotherapy promise an improved efficiency of the anticancer response, as well as higher comfort for the patient. The current advancements in cancer treatment based on nanotechnology exploit the ability of these systems to pass biological barriers to target the tumor cell, as well as tumor cell organelles. In particular, iron oxide NPs are being clinically employed in oncological management due to this ability. When designing an efficient anti-cancer therapy based on NPs, it is important to know and to modulate the phenomena which take place during the interaction of the NPs with the tumor cells, as well as the normal tissues. In this regard, our review is focused on highlighting different approaches to studying the internalization patterns of iron oxide NPs in simple and complex 2D and 3D in vitro cell models, as well as in living tissues, in order to investigate the functionality of an NP-based treatment. Full article

(This article belongs to the Special Issue Biomaterials in Medical Diagnosis and Treatment)

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24 pages, 58669 KiB

Open AccessEditor’s ChoiceArticle

Development of Novel Antibacterial Ti-Nb-Ga Alloys with Low Stiffness for Medical Implant Applications

by Rhianna McHendrie, Ngoc Huu Nguyen, Manh Tuong Nguyen, Khosro Fallahnezhad, Krasimir Vasilev, Vi Khanh Truong and Reza Hashemi

J. Funct. Biomater. 2024, 15(6), 167; https://doi.org/10.3390/jfb15060167 - 17 Jun 2024

Viewed by 784

Abstract

With the rising demand for medical implants and the dominance of implant-associated failures including infections, extensive research has been prompted into the development of novel biomaterials that can offer desirable characteristics. This study develops and evaluates new titanium-based alloys containing gallium additions with [...] Read more.

With the rising demand for medical implants and the dominance of implant-associated failures including infections, extensive research has been prompted into the development of novel biomaterials that can offer desirable characteristics. This study develops and evaluates new titanium-based alloys containing gallium additions with the aim of offering beneficial antibacterial properties while having a reduced stiffness level to minimise the effect of stress shielding when in contact with bone. The focus is on the microstructure, mechanical properties, antimicrobial activity, and cytocompatibility to inform the suitability of the designed alloys as biometals. Novel Ti-33Nb-xGa alloys (x = 3, 5 wt%) were produced via casting followed by homogenisation treatment, where all results were compared to the currently employed alloy Ti-6Al-4V. Optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) results depicted a single beta (β) phase microstructure in both Ga-containing alloys, where Ti-33Nb-5Ga was also dominated by dendritic alpha (α) phase grains in a β-phase matrix. EDS analysis indicated that the α-phase dendrites in Ti-33Nb-5Ga were enriched with titanium, while the β-phase was richer in niobium and gallium elements. Mechanical properties were measured using nanoindentation and microhardness methods, where the Young’s modulus for Ti-33Nb-3Ga and Ti-33Nb-5Ga was found to be 75.4 ± 2.4 and 67.2 ± 1.6 GPa, respectively, a significant reduction of 37% and 44% with respect to Ti-6Al-4V. This reduction helps address the disproportionate Young’s modulus between titanium implant components and cortical bone. Importantly, both alloys successfully achieved superior antimicrobial properties against Gram-negative P. aeruginosa and Gram-positive S. aureus bacteria. Antibacterial efficacy was noted at up to 90 ± 5% for the 3 wt% alloy and 95 ± 3% for the 5 wt% alloy. These findings signify a substantial enhancement of the antimicrobial performance when compared to Ti-6Al-4V which exhibited very small rates (up to 6.3 ± 1.5%). No cytotoxicity was observed in hGF cell lines over 24 h. Cell morphology and cytoskeleton distribution appeared to depict typical morphology with a prominent nucleus, elongated fibroblastic spindle-shaped morphology, and F-actin filamentous stress fibres in a well-defined structure of parallel bundles along the cellular axis. The developed alloys in this work have shown very promising results and are suggested to be further examined towards the use of orthopaedic implant components. Full article

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18 pages, 2145 KiB

Open AccessEditor’s ChoiceReview

A Review on the Current State of Microcapsule-Based Self-Healing Dental Composites

by Xiaoxi Wang and Tian Ding

J. Funct. Biomater. 2024, 15(6), 165; https://doi.org/10.3390/jfb15060165 - 16 Jun 2024

Viewed by 952

Abstract

Resin-based dental composites, commonly used in dentistry, offer several advantages including minimally invasive application, esthetically pleasing appearance, and good physical and mechanical properties. However, these dental composites can be susceptible to microcracks due to various factors in the complex oral environment. These microcracks [...] Read more.

Resin-based dental composites, commonly used in dentistry, offer several advantages including minimally invasive application, esthetically pleasing appearance, and good physical and mechanical properties. However, these dental composites can be susceptible to microcracks due to various factors in the complex oral environment. These microcracks can potentially lead to clinical restoration failure. Conventional materials and methods are inadequate for detecting and repairing these microcracks in situ. Consequently, incorporating self-healing properties into dental composites has become a necessity. Recent years have witnessed rapid advancements in self-healing polymer materials, drawing inspiration from biological bionics. Microcapsule-based self-healing dental composites (SHDCs) represent some of the most prevalent types of self-healing materials utilized in this domain. In this article, we undertake a comprehensive review of the most recent literature, highlighting key insights and findings related to microcapsule-based SHDCs. Our discussion centers particularly on the preparation techniques, application methods, and the promising future of self-healing microcapsules in the field of dentistry. Full article

(This article belongs to the Section Dental Biomaterials)

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20 pages, 7676 KiB

Open AccessEditor’s ChoiceArticle

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants

by Aya Ali, Likhitha Polepalli, Sheetal Chowdhury, Mary A. Carr, Amol V. Janorkar, Mary E. Marquart, Jason A. Griggs, Joel D. Bumgardner and Michael D. Roach

J. Funct. Biomater. 2024, 15(6), 163; https://doi.org/10.3390/jfb15060163 - 14 Jun 2024

Viewed by 673

Abstract

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit [...] Read more.

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit photocatalytic activity (PCA)-driven bacterial resistance under UVA irradiation. Silver additions are reported to enhance PCA and reduce bacterial attachment. This study investigated the effects of silver-doping additions to three established anodization processes. Silver doping showed no significant influence on oxide crystallinity, surface topography, or surface wettability. Oxides from a sulfuric acid anodization process exhibited significantly enhanced PCA after silver doping, but silver-doped oxides produced from phosphoric-acid-containing electrolytes did not. Staphylococcus aureus attachment was also assessed under dark and UVA-irradiated conditions on each oxide. Each oxide exhibited a photocatalytic antimicrobial effect as indicated by significantly decreased bacterial attachment under UVA irradiation compared to dark conditions. However, only the phosphorus-doped mixed anatase and rutile phase oxide exhibited an additional significant reduction in bacteria attachment under UVA irradiation as a result of silver doping. The antimicrobial success of this oxide was attributed to the combination of the mixed phase oxide and higher silver-doping uptake levels. Full article

(This article belongs to the Special Issue Titanium-Based Implants: Advances in Materials and Applications)

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13 pages, 17899 KiB

Open AccessEditor’s ChoiceArticle

A Two-Stage Approach Integrating Provisional Biomaterial-Mediated Stabilization Followed by a Definitive Treatment for Managing Volumetric Muscle Loss Injuries

by Andrew R. Clark, Jonathan Kulwatno, Sergey S. Kanovka, George J. Klarmann, Claudia E. Hernandez, Roman M. Natoli, Todd O. McKinley, Benjamin K. Potter, Christopher L. Dearth and Stephen M. Goldman

J. Funct. Biomater. 2024, 15(6), 160; https://doi.org/10.3390/jfb15060160 - 6 Jun 2024

Viewed by 735

Abstract

Treatment of volumetric muscle loss (VML) faces challenges due to its unique pathobiology and lower priority in severe musculoskeletal injury management. Consequently, a need exists for multi-stage VML treatment strategies to accommodate delayed interventions owing to comorbidity management or prolonged casualty care in [...] Read more.

Treatment of volumetric muscle loss (VML) faces challenges due to its unique pathobiology and lower priority in severe musculoskeletal injury management. Consequently, a need exists for multi-stage VML treatment strategies to accommodate delayed interventions owing to comorbidity management or prolonged casualty care in combat settings. To this end, polyvinyl alcohol (PVA) was used at concentrations of 5%, 7.5%, and 10% to generate provisional muscle void fillers (MVFs) of varying stiffness values (1.125 kPa, 3.700 kPa, and 7.699 kPa) to stabilize VML injuries as part of a two-stage approach. These were implanted into a rat model for a duration of 4 weeks, then explanted and either left untreated (control) or treated through minced muscle grafting (MMG). Additional benchmarks included acute MMG and unrepaired groups. At the MVF explant, the 7.5% PVA group exhibited superior neuromuscular function compared to the 5% and 10% PVA groups, the least fibrosis, and the largest median myofiber size among all groups at the 12-week endpoint. Despite the 7.5% PVA’s superiority amongst the two-stage treatment groups, neuromuscular function was neither improved nor impaired relative to acute treatment benchmarks. This suggests that the future success of a two-stage VML treatment strategy will necessitate a more effective definitive intervention. Full article

(This article belongs to the Special Issue Application of Biomaterials in Tissue Engineering and Regenerative Medicine)

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23 pages, 6703 KiB

Open AccessEditor’s ChoiceReview

Enhancing Guided Bone Regeneration with a Novel Carp Collagen Scaffold: Principles and Applications

by Michele Bujda and Karel Klíma

J. Funct. Biomater. 2024, 15(6), 150; https://doi.org/10.3390/jfb15060150 - 1 Jun 2024

Viewed by 643

Abstract

Bone defects resulting from trauma, surgery, and congenital, infectious, or oncological diseases are a functional and aesthetic burden for patients. Bone regeneration is a demanding procedure, involving a spectrum of molecular processes and requiring the use of various scaffolds and substances, often yielding [...] Read more.

Bone defects resulting from trauma, surgery, and congenital, infectious, or oncological diseases are a functional and aesthetic burden for patients. Bone regeneration is a demanding procedure, involving a spectrum of molecular processes and requiring the use of various scaffolds and substances, often yielding an unsatisfactory result. Recently, the new collagen sponge and its structural derivatives manufactured from European carp (Cyprinus carpio) were introduced and patented. Due to its fish origin, the novel scaffold poses no risk of allergic reactions or transfer of zoonoses and additionally shows superior biocompatibility, mechanical stability, adjustable degradation rate, and porosity. In this review, we focus on the basic principles of bone regeneration and describe the characteristics of an “ideal” bone scaffold focusing on guided bone regeneration. Moreover, we suggest several possible applications of this novel material in bone regeneration processes, thus opening new horizons for further research. Full article

(This article belongs to the Section Bone Biomaterials)

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14 pages, 5642 KiB

Open AccessEditor’s ChoiceArticle

Comparison between Conventional and Digital Workflow in Implant Prosthetic Rehabilitation: A Randomized Controlled Trial

by Massimo Corsalini, Giuseppe Barile, Francesco Ranieri, Edvige Morea, Tommaso Corsalini, Saverio Capodiferro and Rosario Roberto Palumbo

J. Funct. Biomater. 2024, 15(6), 149; https://doi.org/10.3390/jfb15060149 - 31 May 2024

Viewed by 465

Abstract

The progress of digital technologies in dental prosthodontics is fast and increasingly accurate, allowing practitioners to simplify their daily work. These technologies aim to substitute conventional techniques progressively, but their real efficiency and predictability are still under debate. Many systematic reviews emphasize the [...] Read more.

The progress of digital technologies in dental prosthodontics is fast and increasingly accurate, allowing practitioners to simplify their daily work. These technologies aim to substitute conventional techniques progressively, but their real efficiency and predictability are still under debate. Many systematic reviews emphasize the lack of clinical RCTs that compare digital and traditional workflow. To address this evidence, we conducted a three-arm designed clinical RCT, which compares fully digital, combined digital, and analogic and fully analog workflows. We aimed to compare the clinical properties of each workflow regarding interproximal (IC) and occlusal contact (OC), marginal fit, impression time (IT), and patient satisfaction through a VAS scale. In total, 72 patients were included in the study. The IC and OC of the digital workflow were better than the others (p < 0.001), which obtained similar results. No difference between implant–abutment fit was observed (p = 0.5966). The IT was shorter in the digital workflow than the others (p < 0.001), which were similar. Patient satisfaction was higher in the digital workflow than in the conventional one. Despite the limitations, this study’s results support better accuracy and patient tolerance of digital workflow than of conventional techniques, suggesting it as a viable alternative to the latter when performed by clinicians experienced in digital dentistry. Full article

(This article belongs to the Special Issue New Trends in Biomaterials and Implants for Dentistry (2nd Edition))

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14 pages, 4868 KiB

Open AccessEditor’s ChoiceArticle

Laser Ablation Facilitates Implantation of Dynamic Self-Regenerating Cartilage for Articular Cartilage Regeneration

by Yingfang Fan, Fernando P. S. Guastaldi, Gem Runyan, Ying Wang, William A. Farinelli, Mark A. Randolph and Robert W. Redmond

J. Funct. Biomater. 2024, 15(6), 148; https://doi.org/10.3390/jfb15060148 - 29 May 2024

Viewed by 588

Abstract

Objectives: This study investigated a novel strategy for improving regenerative cartilage outcomes. It combines fractional laser treatment with the implantation of neocartilage generated from autologous dynamic Self-Regenerating Cartilage (dSRC). Methods: dSRC was generated in vitro from harvested autologous swine chondrocytes. Culture was performed [...] Read more.

Objectives: This study investigated a novel strategy for improving regenerative cartilage outcomes. It combines fractional laser treatment with the implantation of neocartilage generated from autologous dynamic Self-Regenerating Cartilage (dSRC). Methods: dSRC was generated in vitro from harvested autologous swine chondrocytes. Culture was performed for 2, 4, 8, 10, and 12 weeks to study matrix maturation. Matrix formation and implant integration were also studied in vitro in swine cartilage discs using dSRC or cultured chondrocytes injected into CO₂ laser-ablated or mechanically punched holes. Cartilage discs were cultured for up to 8 weeks, harvested, and evaluated histologically and immunohistochemically. Results: The dSRC matrix was injectable by week 2, and matrices grew larger and more solid with time, generating a contiguous neocartilage matrix by week 8. Hypercellular density in dSRC at week 2 decreased over time and approached that of native cartilage by week 8. All dSRC groups exhibited high glycosaminoglycan (GAG) production, and immunohistochemical staining confirmed that the matrix was typical of normal hyaline cartilage, being rich in collagen type II. After 8 weeks in cartilage lesions in vitro, dSRC constructs generated a contiguous cartilage matrix, while isolated cultured chondrocytes exhibited only a sparse pericellular matrix. dSRC-treated lesions exhibited high GAG production compared to those treated with isolated chondrocytes. Conclusions: Isolated dSRC exhibits hyaline cartilage formation, matures over time, and generates contiguous articular cartilage matrix in fractional laser-created microenvironments in vitro, being well integrated with native cartilage. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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15 pages, 4041 KiB

Open AccessEditor’s ChoiceArticle

Analysis of Gingival Fibroblasts Behaviour in the Presence of 3D-Printed versus Milled Methacrylate-Based Dental Resins—Do We Have a Winner?

by Veaceslav Saramet, Miruna S. Stan, Alexandra Ripszky Totan, Ana Maria Cristina Țâncu, Bianca Voicu-Balasea, Dan Sebastian Enasescu, Florentina Rus-Hrincu and Marina Imre

J. Funct. Biomater. 2024, 15(6), 147; https://doi.org/10.3390/jfb15060147 - 28 May 2024

Viewed by 691

Abstract

Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are based on either subtractive (milling prefabricated blocks) or additive (3D printing) methods, and both are used for obtaining dentistry materials. Our in vitro study aimed to investigate the behavior of human gingival fibroblasts exposed to [...] Read more.

Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are based on either subtractive (milling prefabricated blocks) or additive (3D printing) methods, and both are used for obtaining dentistry materials. Our in vitro study aimed to investigate the behavior of human gingival fibroblasts exposed to methacrylate (MA)-based CAD/CAM milled samples in comparison with that of MA-based 3D-printed samples to better elucidate the mechanisms of cell adaptability and survival. The proliferation of human gingival fibroblasts was measured after 2 and 24 h of incubation in the presence of these samples using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the membrane integrity was assessed through the lactate dehydrogenase release. The level of reactive oxygen species, expression of autophagy-related protein LC3B-I, and detection of GSH and caspase 3/7 were evaluated by fluorescence staining. The MMP-2 levels were measured using a Milliplex MAP kit. The incubation with MA-based 3D-printed samples significantly reduced the viability, by 16% and 28% from control after 2 and 24 h, respectively. There was a 25% and 55% decrease in the GSH level from control after 24 h of incubation with the CAD/CAM milled and 3D-printed samples, respectively. In addition, higher levels of LC3B-I and MMP-2 were obtained after 24 h of incubation with the MA-based 3D samples compared to the CAD/CAM milled ones. Therefore, our results outline that the MA-CAD/CAM milled samples displayed good biocompatibility during 24-h exposure, while MA-3D resins are proper for short-term utilization (less than 24 h). Full article

(This article belongs to the Section Dental Biomaterials)

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12 pages, 1486 KiB

Open AccessEditor’s ChoiceArticle

Biocompatibility of Subperiosteal Dental Implants: Changes in the Expression of Osteogenesis-Related Genes in Osteoblasts Exposed to Differently Treated Titanium Surfaces

by Marco Roy, Elisa Chelucci, Alessandro Corti, Lorenzo Ceccarelli, Mauro Cerea, Barbara Dorocka-Bobkowska, Alfonso Pompella and Simona Daniele

J. Funct. Biomater. 2024, 15(6), 146; https://doi.org/10.3390/jfb15060146 - 27 May 2024

Viewed by 582

Abstract

The use of endosseous dental implants may become unfeasible in the presence of significant maxillary bone atrophy; thus, surgical techniques have been proposed to promote bone regeneration in such cases. However, such techniques are complex and may expose the patient to complications. Subperiosteal [...] Read more.

The use of endosseous dental implants may become unfeasible in the presence of significant maxillary bone atrophy; thus, surgical techniques have been proposed to promote bone regeneration in such cases. However, such techniques are complex and may expose the patient to complications. Subperiosteal implants, being placed between the periosteum and the residual alveolar bone, are largely independent of bone thickness. Such devices had been abandoned due to the complexity of positioning and adaptation to the recipient bone site, but are nowadays witnessing an era of revival following the introduction of new acquisition procedures, new materials, and innovative manufacturing methods. We have analyzed the changes induced in gene and protein expression in C-12720 human osteoblasts by differently surface-modified TiO₂ materials to verify their ability to promote bone formation. The TiO₂ materials tested were (i) raw machined, (ii) electropolished with acid mixture, (iii) sand-blasted + acid-etched, (iv) AlTiColorTM surface, and (v) anodized. All five surfaces efficiently stimulated the expression of markers of osteoblastic differentiation, adhesion, and osteogenesis, such as RUNX2, osteocalcin, osterix, N-cadherin, β-catenin, and osteoprotegerin, while cell viability/proliferation was unaffected. Collectively, our observations document that presently available TiO₂ materials are well suited for the manufacturing of modern subperiosteal implants. Full article

(This article belongs to the Special Issue Orthodontic Biomaterials: From the Past to the Present)

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22 pages, 3618 KiB

Open AccessEditor’s ChoiceArticle

Elasticity Modification of Biomaterials Used in 3D Printing with an Elastin–Silk-like Recombinant Protein

by Violetta Cecuda-Adamczewska, Agnieszka Romanik-Chruścielewska, Katarzyna Kosowska, Iwona Sokołowska, Natalia Łukasiewicz, Paulina Korycka, Katarzyna Florys-Jankowska, Agnieszka Zakrzewska, Michał Wszoła and Marta Klak

J. Funct. Biomater. 2024, 15(6), 141; https://doi.org/10.3390/jfb15060141 - 24 May 2024

Viewed by 672

Abstract

The recombinant structural protein described in this study was designed based on sequences derived from elastin and silk. Silk–elastin hybrid copolymers are characterized by high solubility while maintaining high product flexibility. The phase transition temperature from aqueous solution to hydrogel, as well as [...] Read more.

The recombinant structural protein described in this study was designed based on sequences derived from elastin and silk. Silk–elastin hybrid copolymers are characterized by high solubility while maintaining high product flexibility. The phase transition temperature from aqueous solution to hydrogel, as well as other physicochemical and mechanical properties of such particles, can differ significantly depending on the number of sequence repeats. We present a preliminary characterization of the EJ17zipR protein obtained in high yield in a prokaryotic expression system and efficiently purified via a multistep process. Its addition significantly improves biomaterial’s rheological and mechanical properties, especially elasticity. As a result, EJ17zipR appears to be a promising component for bioinks designed to print spatially complex structures that positively influence both shape retention and the internal transport of body fluids. The results of biological studies indicate that the addition of the studied protein creates a favorable microenvironment for cell adhesion, growth, and migration. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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13 pages, 3667 KiB

Open AccessEditor’s ChoiceArticle

Strategic Use of Biodegradable Temporizing Matrix (BTM) in Wound Healing: A Case Series in Asian Patients

by Angela Chien-Yu Chen, Tsuo-Wu Lin, Ke-Chung Chang and Dun-Hao Chang

J. Funct. Biomater. 2024, 15(5), 136; https://doi.org/10.3390/jfb15050136 - 18 May 2024

Viewed by 1117

Abstract

Skin and soft tissue reconstruction has long been based on the reconstructive ladder. However, a skin substitute has become popular due to its predictable outcomes, without donor-site morbidity. The biodegradable temporizing matrix (BTM; NovoSorb, PolyNovo Ltd., Port Melbourne, Australia) is a synthetic skin [...] Read more.

Skin and soft tissue reconstruction has long been based on the reconstructive ladder. However, a skin substitute has become popular due to its predictable outcomes, without donor-site morbidity. The biodegradable temporizing matrix (BTM; NovoSorb, PolyNovo Ltd., Port Melbourne, Australia) is a synthetic skin substitute that has recently gained its clinical application. Compared with those of other dermal templates, the clinical efficacy and performance of the BTM are not well established, especially among the Asian population. This study aims to share our experience and strategy of using BTM in various wound conditions. The data of patients who underwent skin and soft tissue reconstruction with BTM at a single institution between January 2022 and December 2023 were reviewed. The patient demographics, wound characteristics, surgical details, secondary procedures, and complications were recorded and analyzed. Postoperative 6-month photographs were collected and independently evaluated by two plastic surgeons and two wound care center nurses using the Manchester Scar Scale (MSS). This study included 37 patients, consisting of 22 males and 15 females with a mean age of 51.8 years (range, 18–86 years old). The wound etiologies included trauma (67.6%), necrotizing soft tissue infection (16.2%), burns (10.8%), toe gangrene (2.7%), and scar excision (2.7%). The average wound area covered by BTM was 50.6 ± 47.6 cm². Among the patients, eight received concomitant flap surgery and BTM implantation, 20 (54.1%) underwent subsequent split-thickness skin grafts (STSG), and 17 had small wounds (mean: 21.6 cm²) healed by secondary intention. Infection was the most common complication, affecting six patients (n = 6 [16.2%]), five of whom were treated conservatively, and only one required debridement. Thirty-three patients (89.2%) had good BTM take, and only four had BTM failure, requiring further reconstruction. At the last follow-up, 35 out of the 37 patients (94.6%) achieved successful wound closure, and the total MSS score was 10.44 ± 2.94, indicating a satisfactory scar condition. The patients who underwent BTM grafting without STSG had better scar scores than those who received STSG (8.71 ± 2.60 vs. 11.18 ± 2.84, p = 0.039). In conclusion, the BTM is effective and feasible in treating various wounds, with relatively low complication rates, and it can thus be considered as an alternative for skin and soft tissue reconstruction. When combined with adipofasical flap reconstruction, it achieves a more comprehensive anatomical restoration. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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11 pages, 3600 KiB

Open AccessEditor’s ChoiceArticle

The Impact of Open versus Closed Computer-Aided Design/Computer-Aided Manufacturing Systems on the Marginal Gap of Zirconia-Reinforced Lithium Silicate Single Crowns Evaluated by Scanning Electron Microscopy: A Comparative In Vitro Study

by Asaf Shely, Joseph Nissan, Ofir Rosner, Eran Zenziper, Diva Lugassy, Khadija Abidulkrem and Gil Ben-Izhack

J. Funct. Biomater. 2024, 15(5), 130; https://doi.org/10.3390/jfb15050130 - 15 May 2024

Viewed by 888

Abstract

This study aimed to compare the impact of CAD/CAM closed systems and open systems on the marginal gap of monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns, as both systems are used in everyday dentistry, both chair-side and laboratory. For the closed system, 20 [...] Read more.

This study aimed to compare the impact of CAD/CAM closed systems and open systems on the marginal gap of monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns, as both systems are used in everyday dentistry, both chair-side and laboratory. For the closed system, 20 plastic teeth were scanned by a Primescan intra-oral scanner (IOS), and for the open system, the same number of plastic teeth were scanned by Trios 4 IOS. For the closed system, CEREC software was used, and for the open system, EXOCAD software was used. All 40 ZLS crowns were grinded by the same four-axis machine and cemented with Temp-bond, followed by self-adhesive resin cement. For each type of cement, an evaluation of the marginal gap was conducted by scanning electron microscopy (SEM). Before comparisons between the groups, a Kolmogorov–Smirnov test was performed on the study variables showing a normal distribution (p > 0.05). Independent T tests (α = 0.05) and paired-sample T tests (α = 0.05) were used. The independent T test found no significant mean marginal gap differences in the zirconia-reinforced lithium silicate crowns bonded with Temp-bond and scanned by Primescan (28.09 μm ± 3.06) compared to Trios 4 (28.94 μm ± 3.30) (p = 0.401), and there was no significant mean marginal gap differences in zirconia-reinforced lithium silicate crowns bonded with self-adhesive resin cement (Gcem ONE) and scanned by Primescan (46.70 μm ± 3.80) compared to Trios 4 (47.79 μm ± 2.59) (p = 0.295). Paired-sample T tests showed significantly higher mean marginal gaps with Gcem ONE compared to Temp-bond for the total mean marginal gap when scanning with Primescan (p = 0.0005) or Trios 4 (p = 0.0005). In everyday dentistry, both closed systems (Primescan with Cerec) and open systems (Trios 4 with Exocad) can be used to achieve an acceptable (<120 µm) marginal gap for ZLS CELTRA^® DUO single crowns. There is a significant difference between cementation with Temp-bond and Gcem ONE self-adhesive resin cement (p < 0.05). Full article

(This article belongs to the Special Issue Biomaterials in Dentistry 2024)

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23 pages, 3594 KiB

Open AccessEditor’s ChoiceArticle

Preparation and In Vitro Characterization of Lactococcus lactis-Loaded Alginate Particles as a Promising Delivery Tool for Periodontal Probiotic Therapy

by Bettina Wuttke, Katharina Ekat, Oleksandra Chabanovska, Mario Jackszis, Armin Springer, Praveen Vasudevan, Bernd Kreikemeyer and Hermann Lang

J. Funct. Biomater. 2024, 15(5), 129; https://doi.org/10.3390/jfb15050129 - 15 May 2024

Viewed by 834

Abstract

Probiotic microorganisms are used in a variety of food supplements and medical formulations to promote human health. In periodontal therapy, probiotics are mainly used in the form of gels, tablets or rinses that often tend to leak from the periodontal pocket, resulting in [...] Read more.

Probiotic microorganisms are used in a variety of food supplements and medical formulations to promote human health. In periodontal therapy, probiotics are mainly used in the form of gels, tablets or rinses that often tend to leak from the periodontal pocket, resulting in a strongly reduced therapeutic effect. In this pilot in vitro study, we present biodegradable alginate-based particles as an alternative, highly efficient system for a periodontal delivery of probiotic bacteria to the inflammation site. For this purpose, Lactococcus (L.) lactis was encapsulated using a standardized pump-controlled extrusion-dripping method. Time-dependent bacterial release in artificial saliva was investigated over 9 days. The effect of freeze drying was explored to ensure long-term storage of L. lactis-loaded particles. Additionally, the particles were bound to dentin surface using approved bioadhesives and subjected to shear stress in a hydrodynamic flow chamber that mimics the oral cavity in vitro. Thus, round particles within the range of 0.80–1.75 mm in radius could be produced, whereby the diameter of the dripping tip had the most significant impact on the size. Although both small and large particles demonstrated a similar release trend of L. lactis, the release rate was significantly higher in the former. Following lyophilization, particles could restore their original shape within 4 h in artificial saliva; thereby, the bacterial viability was not affected. The attachment strength to dentin intensified by an adhesive could resist forces between 10 and 25 N/m². Full degradation of the particles was observed after 20 days in artificial saliva. Therefore, alginate particles display a valuable probiotic carrier for periodontal applications that have several crucial advantages over existing preparations: a highly stable form, prolonged continuous release of therapeutic bacteria, precise manufacturing according to required dimensions at the application site, strong attachment to the tooth with low risk of dislocation, high biocompatibility and biodegradability. Full article

(This article belongs to the Special Issue Advanced Biomaterials for Periodontal Regeneration)

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21 pages, 5147 KiB

Open AccessEditor’s ChoiceArticle

Investigating Bioactive-Glass-Infused Gels for Enamel Remineralization: An In Vitro Study

by Zbigniew Raszewski, Katarzyna Chojnacka and Marcin Mikulewicz

J. Funct. Biomater. 2024, 15(5), 119; https://doi.org/10.3390/jfb15050119 - 29 Apr 2024

Cited by 1 | Viewed by 980

Abstract

Objective: Dental hypersensitivity remains widespread, underscoring the need for materials that can effectively seal dental tubules. This study evaluated the potential of bioactive-glass-infused hydroxyethyl cellulose gels in this context. Methods: Five gels were synthesized, each containing 20% bioactive glass (specifically, 45S5, S53P4, Biomin [...] Read more.

Objective: Dental hypersensitivity remains widespread, underscoring the need for materials that can effectively seal dental tubules. This study evaluated the potential of bioactive-glass-infused hydroxyethyl cellulose gels in this context. Methods: Five gels were synthesized, each containing 20% bioactive glass (specifically, 45S5, S53P4, Biomin F, and Biomin C), with an additional blank gel serving as a control. Subjected to two months of accelerated aging at 37 ± 2 °C, these gels were assessed for key properties: viscosity, water disintegration time, pH level, consistency, adhesion to glass, and element release capability. Results: Across the board, the gels facilitated the release of calcium, phosphate, and silicon ions, raising the pH from 9.00 ± 0.10 to 9.7 ± 0.0—a range conducive to remineralization. Dissolution in water occurred within 30–50 min post-application. Viscosity readings showed variability, with 45S5 reaching 6337 ± 24 mPa/s and Biomin F at 3269 ± 18 mPa/s after two months. Initial adhesion for the blank gel was measured at 0.27 ± 0.04 Pa, increasing to 0.73 ± 0.06 Pa for the others over time. Gels can release elements upon contact with water (Ca⁻ Biomin C 104.8 ± 15.7 mg/L; Na⁻ Biomin F 76.30 ± 11.44 mg/L; P⁻ Biomin C 2.623 ± 0.393 mg/L; Si⁻ 45S5-45.15 ± 6.77mg/L, F⁻ Biomin F⁻ 3.256 ± 0.651mg/L; Cl⁻ Biomin C 135.5 ± 20.3 mg/L after 45 min). Conclusions: These findings highlight the gels’ capacity to kickstart the remineralization process by delivering critical ions needed for enamel layer reconstruction. Further exploration in more dynamic, real-world conditions is recommended to fully ascertain their practical utility. Full article

(This article belongs to the Special Issue Technologies and Materials for Application in Dental, Oral and Maxillofacial Engineering)

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17 pages, 5139 KiB

Open AccessEditor’s ChoiceArticle

Resorbable Patient-Specific Implants of Molybdenum for Pediatric Craniofacial Surgery—Proof of Concept in an In Vivo Pilot Study

by Dominik Thomas Hoppe, André Toschka, Nadia Karnatz, Henriette Louise Moellmann, Maximilian Seidl, Lutz van Meenen, Georg Poehle, Christian Redlich and Majeed Rana

J. Funct. Biomater. 2024, 15(5), 118; https://doi.org/10.3390/jfb15050118 - 29 Apr 2024

Viewed by 1039

Abstract

Titanium continues to be the gold standard in the field of osteosynthesis materials. This also applies to pediatric craniofacial surgery. Various resorbable materials have already been developed in order to avoid costly and risky second operations to remove metal in children. However, none [...] Read more.

Titanium continues to be the gold standard in the field of osteosynthesis materials. This also applies to pediatric craniofacial surgery. Various resorbable materials have already been developed in order to avoid costly and risky second operations to remove metal in children. However, none of these resorbable materials have been able to completely replace the previous gold standard, titanium, in a satisfactory manner. This has led to the need for a new resorbable osteosynthesis material that fulfills the requirements for biocompatibility, stability, and uniform resorption. In our previous in vitro and in vivo work, we were able to show that molybdenum fulfills these requirements. To further confirm these results, we conducted a proof of concept in four domestic pigs, each of which was implanted with a resorbable molybdenum implant. The animals were then examined daily for local inflammatory parameters. After 54 days, the animals were euthanized with subsequent computer tomography imaging. We also removed the implants together with the surrounding tissue and parts of the spleen, liver, and kidney for histopathological evaluation. The molybdenum implants were also analyzed metallographically and using scanning electron microscopy. A blood sample was taken pre- and post-operatively. None of the animals showed clinical signs of inflammation over the entire test period. Histopathologically, good tissue compatibility was found. Early signs of degradation were observed after 54 days, which were not sufficient for major resorption. Resorption is expected with longer in situ residence times based on results of similar earlier investigations. Full article

(This article belongs to the Special Issue Functional Composites for Bone Implants and Osseointegration)

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17 pages, 3913 KiB

Open AccessEditor’s ChoiceArticle

Apatite-Forming Ability and Visible Light-Enhanced Antibacterial Activity of CuO-Supported TiO₂ Formed on Titanium by Chemical and Thermal Treatments

by Po-Cheng Sung, Taishi Yokoi, Masaya Shimabukuro, Takayuki Mokudai and Masakazu Kawashita

J. Funct. Biomater. 2024, 15(5), 114; https://doi.org/10.3390/jfb15050114 - 24 Apr 2024

Viewed by 1249

Abstract

Titanium with apatite-forming ability as well as antibacterial activity is useful as a component of antibacterial dental implants. When Ti was subjected to hydrogen peroxide (H₂O₂), copper acetate (Cu(OAc)₂), and heat (H₂O₂-Cu(OAc)₂ [...] Read more.

Titanium with apatite-forming ability as well as antibacterial activity is useful as a component of antibacterial dental implants. When Ti was subjected to hydrogen peroxide (H₂O₂), copper acetate (Cu(OAc)₂), and heat (H₂O₂-Cu(OAc)₂-heat) treatments, a network structure of anatase and rutile titanium dioxide (TiO₂) and fine copper oxide (CuO) particles was formed on the Ti surface. The resulting samples accumulated a dense and uniform apatite layer on the surface when incubated in simulated body fluid and showed enhanced antibacterial activity against Escherichia coli and Staphylococcus aureus under visible-light irradiation. Electron spin resonance spectra of H₂O₂-Cu(OAc)₂-heat-treated samples showed that hydroxyl radicals (·OH) were generated from the samples, and the concentration of ·OH increased with increasing Cu concentration of the Cu(OAc)₂ solution. The enhanced antibacterial activity of these samples under visible-light irradiation may be attributable to the generation of ·OH from samples. These results suggest that Ti implants obtained using H₂O₂-Cu(OAc)₂-heat treatments and subjected to regular or on-demand visible-light irradiation may provide a decreased risk of peri-implantitis. Full article

(This article belongs to the Special Issue Active Biomedical Materials and Their Applications)

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18 pages, 7401 KiB

Open AccessEditor’s ChoiceArticle

Hydrogels and Carbon Nanotubes: Composite Electrode Materials for Long-Term Electrocardiography Monitoring

by Leszek Kolodziej, Olga Iwasińska-Kowalska, Grzegorz Wróblewski, Tomasz Giżewski, Małgorzata Jakubowska and Agnieszka Lekawa-Raus

J. Funct. Biomater. 2024, 15(5), 113; https://doi.org/10.3390/jfb15050113 - 23 Apr 2024

Viewed by 985

Abstract

This paper presents methods for developing high-performance interface electrode materials designed to enhance signal collection efficacy during long-term (over 24 h) electrocardiography (ECG) monitoring. The electrode materials are fabricated by integrating commercial ECG liquid hydrogels with carbon nanotubes (CNTs), which are widely utilized [...] Read more.

This paper presents methods for developing high-performance interface electrode materials designed to enhance signal collection efficacy during long-term (over 24 h) electrocardiography (ECG) monitoring. The electrode materials are fabricated by integrating commercial ECG liquid hydrogels with carbon nanotubes (CNTs), which are widely utilized in dry-electrode technologies and extensively discussed in the current scientific literature. The composite materials are either prepared by dispersing CNTs within the commercial liquid hydrogel matrix or by encasing the hydrogels in macroscopic CNT films. Both approaches ensure the optimal wetting of the epidermis via the hydrogels, while the CNTs reduce material impedance and stabilize the drying process. The resulting electrode materials maintain their softness, allowing for micro-conformal skin attachment, and are biocompatible. Empirical testing confirms that the ECG electrodes employing these hybrid hydrogels adhere to relevant standards for durations exceeding 24 h. These innovative hybrid solutions merge the benefits of both wet and dry ECG electrode technologies, potentially facilitating the extended monitoring of ECG signals and thus advancing the diagnosis and treatment of various cardiac conditions. Full article

(This article belongs to the Section Biomaterials and Devices for Healthcare Applications)

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12 pages, 978 KiB

Open AccessEditor’s ChoiceArticle

Effects of Erythropoietin-Promoted Fracture Healing on Bone Turnover Markers in Cats

by Radina Vasileva, Tsvetan Chaprazov and Aneliya Milanova

J. Funct. Biomater. 2024, 15(4), 106; https://doi.org/10.3390/jfb15040106 - 17 Apr 2024

Viewed by 1220

Abstract

In orthopaedics, erythropoietin (EPO) is applied in the preoperative management of anaemic patients, but also as a stimulating factor to assist bone regeneration due to its angiogenic and osteoinductive potential. Since orthopaedists mainly rely on their clinical experience to assess bone healing, additional [...] Read more.

In orthopaedics, erythropoietin (EPO) is applied in the preoperative management of anaemic patients, but also as a stimulating factor to assist bone regeneration due to its angiogenic and osteoinductive potential. Since orthopaedists mainly rely on their clinical experience to assess bone healing, additional and more objective methods such as studying the dynamics of bone markers are needed. Therefore, the aim of this study was to investigate the plasma activity of bone-specific alkaline phosphatase (BALP), the N-terminal propeptide of type I collagen (PINP), the C-terminal telopeptide of type I collagen (CTX), and deoxypyridinoline (DPD) during the first 2 months of healing of comminuted fractures in cats, either non-stimulated or locally stimulated with recombinant human erythropoietin (rhEPO). The study included twelve cats of mixed breeds, aged 7.2 ± 4 months, weighing 2.11 ± 1.1 kg, with comminuted diaphyseal fractures of the femur. Surgical treatment with plate osteosynthesis was performed in all animals. The cats were randomly divided into two groups—a control (n = 6) and an EPO group (n = 6). The locally applied EPO leads to the increased activity of bone formation markers (BALP and PINP) during the second week after the osteosynthesis, preceding the peaks in the control group by two weeks. The studied bone resorption markers (DPD, CTX) varied insignificantly during the studied period. In conclusion, erythropoietin could serve as a promoter of bone healing in comminuted fractures in cats. Full article

(This article belongs to the Special Issue Advances in Bone Substitute Biomaterials)

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13 pages, 14329 KiB

Open AccessEditor’s ChoiceArticle

Strontium-Doped Bioglass-Laden Gelatin Methacryloyl Hydrogels for Vital Pulp Therapy

by Sepideh Aminmansour, Ana Beatriz Gomes de Carvalho, Lais Medeiros Cardoso, Caroline Anselmi, Maedeh Rahimnejad, Renan Dal-Fabbro, Erika Benavides, Tiago Moreira Bastos Campos, Alexandre Luiz Souto Borges and Marco C. Bottino

J. Funct. Biomater. 2024, 15(4), 105; https://doi.org/10.3390/jfb15040105 - 17 Apr 2024

Viewed by 1329

Abstract

This study aimed to develop gelatin methacryloyl (GelMA)-injectable hydrogels incorporated with 58S bioactive glass/BG-doped with strontium for vital pulp therapy applications. GelMA hydrogels containing 0% (control), 5%, 10%, and 20% BG (w/v) were prepared. Their morphological and chemical properties [...] Read more.

This study aimed to develop gelatin methacryloyl (GelMA)-injectable hydrogels incorporated with 58S bioactive glass/BG-doped with strontium for vital pulp therapy applications. GelMA hydrogels containing 0% (control), 5%, 10%, and 20% BG (w/v) were prepared. Their morphological and chemical properties were evaluated by scanning electron microscopy/SEM, energy dispersive spectroscopy/EDS, and Fourier transform infrared spectroscopy/FTIR (n = 3). Their swelling capacity and degradation ratio were also measured (n = 4). Cell viability (n = 8), mineralized matrix formation, cell adhesion, and spreading (n = 6) on DPSCs were evaluated. Data were analyzed using ANOVA/post hoc tests (α = 5%). SEM and EDS characterization confirmed the incorporation of BG particles into the hydrogel matrix, showing GelMA’s (C, O) and BG’s (Si, Cl, Na, Sr) chemical elements. FTIR revealed the main chemical groups of GelMA and BG, as ~1000 cm⁻¹ corresponds to Si-O and ~1440 cm⁻¹ to C-H. All the formulations were degraded by day 12, with a lower degradation ratio observed for GelMA+BG20%. Increasing the concentration of BG resulted in a lower mass swelling ratio. Biologically, all the groups were compatible with cells (p > 0.6196), and cell adhesion increased over time, irrespective of BG concentration, indicating great biocompatibility. GelMA+BG5% demonstrated a higher deposition of mineral nodules over 21 days (p < 0.0001), evidencing the osteogenic potential of hydrogels. GelMA hydrogels incorporated with BG present great cytocompatibility, support cell adhesion, and have a clinically relevant degradation profile and suitable mineralization potential, supporting their therapeutic potential as promising biomaterials for pulp capping. Full article

(This article belongs to the Section Dental Biomaterials)

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29 pages, 4486 KiB

Open AccessEditor’s ChoiceReview

Zinc Oxide-Based Nanomaterials for Microbiostatic Activities: A Review

by Alemtsehay Tesfay Reda, Jae Yeon Park and Yong Tae Park

J. Funct. Biomater. 2024, 15(4), 103; https://doi.org/10.3390/jfb15040103 - 15 Apr 2024

Viewed by 1925

Abstract

The world is fighting infectious diseases. Therefore, effective antimicrobials are required to prevent the spread of microbes and protect human health. Zinc oxide (ZnO) nano-materials are known for their antimicrobial activities. Because of their distinctive physical and chemical characteristics, they can be used [...] Read more.

The world is fighting infectious diseases. Therefore, effective antimicrobials are required to prevent the spread of microbes and protect human health. Zinc oxide (ZnO) nano-materials are known for their antimicrobial activities. Because of their distinctive physical and chemical characteristics, they can be used in medical and environmental applications. ZnO-based composites are among the leading sources of antimicrobial research. They are effective at killing (microbicidal) and inhibiting the growth (microbiostatic) of numerous microorganisms, such as bacteria, viruses, and fungi. Although most studies have focused on the microbicidal features, there is a lack of reviews on their microbiostatic effects. This review provides a detailed overview of available reports on the microbiostatic activities of ZnO-based nano-materials against different microorganisms. Additionally, the factors that affect the efficacy of these materials, their time course, and a comparison of the available antimicrobials are highlighted in this review. The basic properties of ZnO, challenges of working with microorganisms, and working mechanisms of microbiostatic activities are also examined. This review underscores the importance of further research to better understand ZnO-based nano-materials for controlling microbial growth. Full article

(This article belongs to the Special Issue Innovative Biomaterials for Tissue Engineering: Regeneration of Soft and Hard Tissues—Volume II)

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15 pages, 4307 KiB

Open AccessEditor’s ChoiceArticle

Functionalization of PCL-Based Fiber Scaffolds with Different Sources of Calcium and Phosphate and Odontogenic Potential on Human Dental Pulp Cells

by Caroline Anselmi, Igor Paulino Mendes Soares, Rafaella Lara Maia Mota, Maria Luísa Leite, Rafael Antonio de Oliveira Ribeiro, Lídia de Oliveira Fernandes, Marco C. Bottino, Carlos Alberto de Souza Costa and Josimeri Hebling

J. Funct. Biomater. 2024, 15(4), 97; https://doi.org/10.3390/jfb15040097 - 10 Apr 2024

Viewed by 1057

Abstract

This study investigated the incorporation of sources of calcium, phosphate, or both into electrospun scaffolds and evaluated their bioactivity on human dental pulp cells (HDPCs). Additionally, scaffolds incorporated with calcium hydroxide (CH) were characterized for degradation, calcium release, and odontogenic differentiation by HDPCs. [...] Read more.

This study investigated the incorporation of sources of calcium, phosphate, or both into electrospun scaffolds and evaluated their bioactivity on human dental pulp cells (HDPCs). Additionally, scaffolds incorporated with calcium hydroxide (CH) were characterized for degradation, calcium release, and odontogenic differentiation by HDPCs. Polycaprolactone (PCL) was electrospun with or without 0.5% w/v of calcium hydroxide (PCL + CH), nano-hydroxyapatite (PCL + nHA), or β-glycerophosphate (PCL + βGP). SEM/EDS analysis confirmed fibrillar morphology and particle incorporation. HDPCs were cultured on the scaffolds to assess cell viability, adhesion, spreading, and mineralized matrix formation. PCL + CH was also evaluated for gene expression of odontogenic markers (RT-qPCR). Data were submitted to ANOVA and Student’s t-test (α = 5%). Added CH increased fiber diameter and interfibrillar spacing, whereas βGP decreased both. PCL + CH and PCL + nHA improved HDPC viability, adhesion, and proliferation. Mineralization was increased eightfold with PCL + CH. Scaffolds containing CH gradually degraded over six months, with calcium release within the first 140 days. CH incorporation upregulated DSPP and DMP1 expression after 7 and 14 days. In conclusion, CH- and nHA-laden PCL fiber scaffolds were cytocompatible and promoted HDPC adhesion, proliferation, and mineralized matrix deposition. PCL + CH scaffolds exhibit a slow degradation profile, providing sustained calcium release and stimulating HDPCs to upregulate odontogenesis marker genes. Full article

(This article belongs to the Special Issue Biomaterials for Dental Pulp Tissue)

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33 pages, 4014 KiB

Open AccessEditor’s ChoiceReview

Advancements in Hybrid Cellulose-Based Films: Innovations and Applications in 2D Nano-Delivery Systems

by Ghazaleh Ramezani, Ion Stiharu, Theo G. M. van de Ven and Vahe Nerguizian

J. Funct. Biomater. 2024, 15(4), 93; https://doi.org/10.3390/jfb15040093 - 4 Apr 2024

Cited by 1 | Viewed by 1273

Abstract

This review paper delves into the realm of hybrid cellulose-based materials and their applications in 2D nano-delivery systems. Cellulose, recognized for its biocompatibility, versatility, and renewability, serves as the core matrix for these nanomaterials. The paper offers a comprehensive overview of the latest [...] Read more.

This review paper delves into the realm of hybrid cellulose-based materials and their applications in 2D nano-delivery systems. Cellulose, recognized for its biocompatibility, versatility, and renewability, serves as the core matrix for these nanomaterials. The paper offers a comprehensive overview of the latest advancements in the creation, analysis, and application of these materials, emphasizing their significance in nanotechnology and biomedical domains. It further illuminates the integration of nanomaterials and advanced synthesis techniques that have significantly improved the mechanical, chemical, and biological properties of hybrid cellulose-based materials. Full article

(This article belongs to the Special Issue Feature Review Papers on Functional Biomaterials)

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11 pages, 533 KiB

Open AccessEditor’s ChoiceReview

Comparison of Zirconia Implant Surface Modifications for Optimal Osseointegration

by Hyun Woo Jin, Sammy Noumbissi and Thomas G. Wiedemann

J. Funct. Biomater. 2024, 15(4), 91; https://doi.org/10.3390/jfb15040091 - 2 Apr 2024

Viewed by 1484

Abstract

Zirconia ceramic implants are commercially available from a rapidly growing number of manufacturers. Macroscopic and microscopic surface design and characteristics are considered to be key determining factors in the success of the osseointegration process. It is, therefore, crucial to assess which surface modification [...] Read more.

Zirconia ceramic implants are commercially available from a rapidly growing number of manufacturers. Macroscopic and microscopic surface design and characteristics are considered to be key determining factors in the success of the osseointegration process. It is, therefore, crucial to assess which surface modification promotes the most favorable biological response. The purpose of this study was to conduct a comparison of modern surface modifications that are featured in the most common commercially available zirconia ceramic implant systems. A review of the currently available literature on zirconia implant surface topography and the associated bio-physical factors was conducted, with a focus on the osseointegration of zirconia surfaces. After a review of the selected articles for this study, commercially available zirconia implant surfaces were all modified using subtractive protocols. Commercially available ceramic implant surfaces were modified or enhanced using sandblasting, acid etching, laser etching, or combinations of the aforementioned. From our literature review, laser-modified surfaces emerged as the ones with the highest surface roughness and bone–implant contact (BIC). It was also found that surface roughness could be controlled to achieve optimal roughness by modifying the laser output power during manufacturing. Furthermore, laser surface modification induced a very low amount of preload microcracks in the zirconia. Osteopontin (OPN), an early–late osteogenic differentiation marker, was significantly upregulated in laser-treated surfaces. Moreover, surface wettability was highest in laser-treated surfaces, indicating favorable hydrophilicity and thus promoting early bone forming, cell adhesion, and subsequent maturation. Sandblasting followed by laser modification and sandblasting followed by acid etching and post-milling heat treatment (SE-H) surfaces featured comparable results, with favorable biological responses around zirconia implants. Full article

(This article belongs to the Special Issue Surface Properties and Modifications of Zirconia)

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17 pages, 3630 KiB

Open AccessEditor’s ChoiceArticle

A New Hyaluronic Emulgel of Hesperetin for Topical Application—An In Vitro Evaluation

by Raquel Taléns-Visconti, Yousra Belarbi, Octavio Díez-Sales, Jesus Vicente de Julián-Ortiz, Ofelia Vila-Busó and Amparo Nácher

J. Funct. Biomater. 2024, 15(4), 89; https://doi.org/10.3390/jfb15040089 - 1 Apr 2024

Viewed by 1219

Abstract

The present study aimed to formulate and characterize a hesperetin formulation to achieve adequate deposition and retention of hesperetin in the epidermis as a target for some cosmetic/dermatological actions. To derive the final emulgel, various formulations incorporating different proportions of Polysorbate 80 and [...] Read more.

The present study aimed to formulate and characterize a hesperetin formulation to achieve adequate deposition and retention of hesperetin in the epidermis as a target for some cosmetic/dermatological actions. To derive the final emulgel, various formulations incorporating different proportions of Polysorbate 80 and hyaluronic acid underwent testing through a Box–Behnken experimental design. Nine formulations were created until the targeted emulgel properties were achieved. This systematic approach, following the principles of a design of experiment (DoE) methodology, adheres to a quality-by-design (QbD) paradigm, ensuring a robust and purposeful formulation and highlighting the commitment to a quality-driven design approach. The emulsions were developed using the phase inversion method, optimizing the emulgel with the incorporation of hyaluronic acid. Physically stable optimized emulgels were evaluated for their globule size, surface charge, viscosity, pH, electrical conductivity, and hesperetin content. These assays, along with the temperature swing test, were used to select the optimal formulation. It was characterized by a droplet size, d[4,3], of 4.02 μm, a Z-potential of −27.8 mV, an O/W sign, a pH of 5.2, and a creamy texture and proved to be stable for at least 2 months at room temperature. Additionally, in vitro release kinetics from the selected emulgel exhibited a sustained release profile of hesperetin. Skin assays revealed adequate retention of hesperetin in the human epidermis with minimum permeation. Altogether, these results corroborate the promising future of the proposed emulgel in cosmetic or dermatological use on healthy or diseased skin. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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14 pages, 6661 KiB

Open AccessEditor’s ChoiceArticle

Synthesis of Alginate/Collagen Bioink for Bioprinting Respiratory Tissue Models

by Amanda Zimmerling, Yan Zhou and Xiongbiao Chen

J. Funct. Biomater. 2024, 15(4), 90; https://doi.org/10.3390/jfb15040090 - 1 Apr 2024

Viewed by 1593

Abstract

Synthesis of bioinks for bioprinting of respiratory tissue requires considerations related to immunogenicity, mechanical properties, printability, and cellular compatibility. Biomaterials can be tailored to provide the appropriate combination of these properties through the synergy of materials with individual pros and cons. Sodium alginate, [...] Read more.

Synthesis of bioinks for bioprinting of respiratory tissue requires considerations related to immunogenicity, mechanical properties, printability, and cellular compatibility. Biomaterials can be tailored to provide the appropriate combination of these properties through the synergy of materials with individual pros and cons. Sodium alginate, a water-soluble polymer derived from seaweed, is a cheap yet printable biomaterial with good structural properties; however, it lacks physiological relevance and cell binding sites. Collagen, a common component in the extra cellular matrix of many tissues, is expensive and lacks printability; however, it is highly biocompatible and exhibits sites for cellular binding. This paper presents our study on the synthesis of bioinks from alginate and collagen for use in bioprinting respiratory tissue models. Bioinks were synthesized from 40 mg/mL (4%) alginate and 3 mg/mL (0.3%) collagen in varying ratios (1:0, 4:1, 3:1, 2:1, and 1:1); then examined in terms of rheological properties, printability, compressive, and tensile properties and cellular compatibility. The results illustrate that the ratio of alginate to collagen has a profound impact on bioink performance and that, among the examined ratios, the 3:1 ratio is the most appropriate for use in bioprinting respiratory tissue scaffolds. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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17 pages, 1389 KiB

Open AccessEditor’s ChoiceArticle

Influence of Magnesium Degradation on Schwannoma Cell Responses to Nerve Injury Using an In Vitro Injury Model

by Krathika Bhat, Lisa Hanke, Heike Helmholz, Eckhard Quandt, Sarah Pixley and Regine Willumeit-Römer

J. Funct. Biomater. 2024, 15(4), 88; https://doi.org/10.3390/jfb15040088 - 31 Mar 2024

Viewed by 1280

Abstract

Nerve guidance conduits for peripheral nerve injuries can be improved using bioactive materials such as magnesium (Mg) and its alloys, which could provide both structural and trophic support. Therefore, we investigated whether exposure to Mg and Mg-1.6wt%Li thin films (Mg/Mg-1.6Li) would alter acute [...] Read more.

Nerve guidance conduits for peripheral nerve injuries can be improved using bioactive materials such as magnesium (Mg) and its alloys, which could provide both structural and trophic support. Therefore, we investigated whether exposure to Mg and Mg-1.6wt%Li thin films (Mg/Mg-1.6Li) would alter acute Schwann cell responses to injury. Using the RT4-D6P2T Schwannoma cell line (SCs), we tested extracts from freeze-killed cells (FKC) and nerves (FKN) as in vitro injury stimulants. Both FKC and FKN induced SC release of the macrophage chemoattractant protein 1 (MCP-1), a marker of the repair SC phenotype after injury. Next, FKC-stimulated cells exposed to Mg/Mg-1.6Li reduced MCP-1 release by 30%, suggesting that these materials could have anti-inflammatory effects. Exposing FKC-treated cells to Mg/Mg-1.6Li reduced the gene expression of the nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), and myelin protein zero (MPZ), but not the p75 neurotrophin receptor. In the absence of FKC, Mg/Mg-1.6Li treatment increased the expression of NGF, p75, and MPZ, which can be beneficial to nerve regeneration. Thus, the presence of Mg can differentially alter SCs, depending on the microenvironment. These results demonstrate the applicability of this in vitro nerve injury model, and that Mg has wide-ranging effects on the repair SC phenotype. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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35 pages, 8310 KiB

Open AccessEditor’s ChoiceReview

Biomaterials for Regenerative Cranioplasty: Current State of Clinical Application and Future Challenges

by Lizhe He

J. Funct. Biomater. 2024, 15(4), 84; https://doi.org/10.3390/jfb15040084 - 28 Mar 2024

Viewed by 1633

Abstract

Acquired cranial defects are a prevalent condition in neurosurgery and call for cranioplasty, where the missing or defective cranium is replaced by an implant. Nevertheless, the biomaterials in current clinical applications are hardly exempt from long-term safety and comfort concerns. An appealing solution [...] Read more.

Acquired cranial defects are a prevalent condition in neurosurgery and call for cranioplasty, where the missing or defective cranium is replaced by an implant. Nevertheless, the biomaterials in current clinical applications are hardly exempt from long-term safety and comfort concerns. An appealing solution is regenerative cranioplasty, where biomaterials with/without cells and bioactive molecules are applied to induce the regeneration of the cranium and ultimately repair the cranial defects. This review examines the current state of research, development, and translational application of regenerative cranioplasty biomaterials and discusses the efforts required in future research. The first section briefly introduced the regenerative capacity of the cranium, including the spontaneous bone regeneration bioactivities and the presence of pluripotent skeletal stem cells in the cranial suture. Then, three major types of biomaterials for regenerative cranioplasty, namely the calcium phosphate/titanium (CaP/Ti) composites, mineralised collagen, and 3D-printed polycaprolactone (PCL) composites, are reviewed for their composition, material properties, and findings from clinical trials. The third part discusses perspectives on future research and development of regenerative cranioplasty biomaterials, with a considerable portion based on issues identified in clinical trials. This review aims to facilitate the development of biomaterials that ultimately contribute to a safer and more effective healing of cranial defects. Full article

(This article belongs to the Special Issue Bone Tissue Engineering: Recent Advances and Translation to Clinical Application)

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21 pages, 1566 KiB

Open AccessEditor’s ChoiceReview

Graphene in 3D Bioprinting

by Rahul Patil and Stella Alimperti

J. Funct. Biomater. 2024, 15(4), 82; https://doi.org/10.3390/jfb15040082 - 25 Mar 2024

Viewed by 2085

Abstract

Three-dimensional (3D) bioprinting is a fast prototyping fabrication approach that allows the development of new implants for tissue restoration. Although various materials have been utilized for this process, they lack mechanical, electrical, chemical, and biological properties. To overcome those limitations, graphene-based materials demonstrate [...] Read more.

Three-dimensional (3D) bioprinting is a fast prototyping fabrication approach that allows the development of new implants for tissue restoration. Although various materials have been utilized for this process, they lack mechanical, electrical, chemical, and biological properties. To overcome those limitations, graphene-based materials demonstrate unique mechanical and electrical properties, morphology, and impermeability, making them excellent candidates for 3D bioprinting. This review summarizes the latest developments in graphene-based materials in 3D printing and their application in tissue engineering and regenerative medicine. Over the years, different 3D printing approaches have utilized graphene-based materials, such as graphene, graphene oxide (GO), reduced GO (rGO), and functional GO (fGO). This process involves controlling multiple factors, such as graphene dispersion, viscosity, and post-curing, which impact the properties of the 3D-printed graphene-based constructs. To this end, those materials combined with 3D printing approaches have demonstrated prominent regeneration potential for bone, neural, cardiac, and skin tissues. Overall, graphene in 3D bioprinting may pave the way for new regenerative strategies with translational implications in orthopedics, neurology, and cardiovascular areas. Full article

(This article belongs to the Special Issue 3D Printing Applications in Regenerative Medicine and Biomedical Devices)

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26 pages, 3537 KiB

Open AccessEditor’s ChoiceReview

Advancements in Biomedical Applications of Calcium Phosphate Glass and Glass-Based Devices—A Review

by Jawad T. Pandayil, Nadia G. Boetti and Davide Janner

J. Funct. Biomater. 2024, 15(3), 79; https://doi.org/10.3390/jfb15030079 - 21 Mar 2024

Viewed by 1676

Abstract

Calcium phosphate (CaP) glass has recently gained popularity as a promising material for a wide range of biomedical applications. Recent developments have seen CaP glasses moving from a passive implant material to an active degradable material, particularly as a major constituent of bioresorbable [...] Read more.

Calcium phosphate (CaP) glass has recently gained popularity as a promising material for a wide range of biomedical applications. Recent developments have seen CaP glasses moving from a passive implant material to an active degradable material, particularly as a major constituent of bioresorbable photonic devices. This holds great promise in advanced biomedical applications, since the main constituents of CaP glasses are present in the human body. In this review, the progressive advancements in the biomedical applications of calcium phosphate glass-based devices over the past 50 years are discussed. An overview of their role as reinforcing agents and the studies on doping their matrices for ion releasing and drug and gene delivery are reviewed. Recent applications of CaP glass and fibers in soft-tissue engineering and their potential for optical quality bioresorbable devices are then discussed along with the current challenges and potential future directions, emphasizing the promising role of CaP glass in the next generation of biomaterials. Considering their progress and potential in performing several biomedical functionalities over time, CaP glass-based devices hold promise for becoming enabling tools as an implantable, bioresorbable, multifunctional class of devices in future biomedicine. Full article

(This article belongs to the Special Issue Bioactive Glasses in Medical Applications)

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18 pages, 5077 KiB

Open AccessEditor’s ChoiceArticle

Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C₆₀/Polyurethane Composite Films

by Zoran M. Marković, Milica D. Budimir Filimonović, Dušan D. Milivojević, Janez Kovač and Biljana M. Todorović Marković

J. Funct. Biomater. 2024, 15(3), 73; https://doi.org/10.3390/jfb15030073 - 17 Mar 2024

Cited by 3 | Viewed by 1660

Abstract

The cost of treatment of antibiotic-resistant pathogens is on the level of tens of billions of dollars at the moment. It is of special interest to reduce or solve this problem using antimicrobial coatings, especially in hospitals or other healthcare facilities. The bacteria [...] Read more.

The cost of treatment of antibiotic-resistant pathogens is on the level of tens of billions of dollars at the moment. It is of special interest to reduce or solve this problem using antimicrobial coatings, especially in hospitals or other healthcare facilities. The bacteria can transfer from medical staff or contaminated surfaces to patients. In this paper, we focused our attention on the antibacterial and antibiofouling activities of two types of photodynamic polyurethane composite films doped with carbon polymerized dots (CPDs) and fullerene C₆₀. Detailed atomic force, electrostatic force and viscoelastic microscopy revealed topology, nanoelectrical and nanomechanical properties of used fillers and composites. A relationship between the electronic structure of the nanocarbon fillers and the antibacterial and antibiofouling activities of the composites was established. Thorough spectroscopic analysis of reactive oxygen species (ROS) generation was conducted for both composite films, and it was found that both of them were potent antibacterial agents against nosocomial bacteria (Klebsiela pneumoniae, Proteus mirabilis, Salmonela enterica, Enterococcus faecalis, Enterococcus epidermis and Pseudomonas aeruginosa). Antibiofouling testing of composite films indicated that the CPDs/PU composite films eradicated almost completely the biofilms of Pseudomonas aeruginosa and Staphylococcus aureus and about 50% of Escherichia coli biofilms. Full article

(This article belongs to the Special Issue Photodynamic Therapy of Cancer, Microbes and Viruses)

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15 pages, 2586 KiB

Open AccessEditor’s ChoiceArticle

Reduction in Pathogenic Biofilms by the Photoactive Composite of Bacterial Cellulose and Nanochitosan Dots under Blue and Green Light

by Danica Z. Zmejkoski, Nemanja M. Zdravković, Milica D. Budimir Filimonović, Vladimir B. Pavlović, Svetlana V. Butulija, Dušan D. Milivojević, Zoran M. Marković and Biljana M. Todorović Marković

J. Funct. Biomater. 2024, 15(3), 72; https://doi.org/10.3390/jfb15030072 - 14 Mar 2024

Cited by 2 | Viewed by 1532

Abstract

In this study, nanochitosan dots (ChiDs) were synthesized using gamma rays and encapsulated in bacterial cellulose (BC) polymer matrix for antibiofilm potential in photodynamic therapy. The composites were analyzed for structural changes using SEM, AFM, FTIR, XRD, EPR, and porosity measurements. Additionally, ChiD [...] Read more.

In this study, nanochitosan dots (ChiDs) were synthesized using gamma rays and encapsulated in bacterial cellulose (BC) polymer matrix for antibiofilm potential in photodynamic therapy. The composites were analyzed for structural changes using SEM, AFM, FTIR, XRD, EPR, and porosity measurements. Additionally, ChiD release was assessed. The results showed that the chemical composition remained unaltered, but ChiD agglomerates embedded in BC changed shape (1.5–2.5 µm). Bacterial cellulose fibers became deformed and interconnected, with increased surface roughness and porosity and decreased crystallinity. No singlet oxygen formation was observed, and the total amount of released ChiD was up to 16.10%. Antibiofilm activity was higher under green light, with reductions ranging from 48 to 57% under blue light and 78 to 85% under green light. Methicillin-resistant Staphylococcus aureus was the most sensitive strain. The new photoactive composite hydrogels show promising potential for combating biofilm-related infections. Full article

(This article belongs to the Section Biomaterials for Cancer Therapies)

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18 pages, 3793 KiB

Open AccessEditor’s ChoiceArticle

Formulative Study and Characterization of Novel Biomaterials Based on Chitosan/Hydrolyzed Collagen Films

by Tomás Martínez Rodríguez, Caterina Valentino, Francisco Ramón Rodríguez Pozo, Pablo Hernández Benavides, Francisco Arrebola Vargas, José Manuel Paredes, Claro Ignacio Sainz-Díaz, Guillermo R. Iglesias, Silvia Rossi, Giuseppina Sandri, María del Mar Medina Pérez and Carola Aguzzi

J. Funct. Biomater. 2024, 15(3), 69; https://doi.org/10.3390/jfb15030069 - 11 Mar 2024

Viewed by 1566

Abstract

To date, the need for biomaterials capable of improving the treatment of chronic skin wounds remains a clinical challenge. The aim of the present work is to formulate and characterize chitosan (Cs)/hydrolyzed collagen (HC) films as potential biomaterials with improved mechanical and hydration [...] Read more.

To date, the need for biomaterials capable of improving the treatment of chronic skin wounds remains a clinical challenge. The aim of the present work is to formulate and characterize chitosan (Cs)/hydrolyzed collagen (HC) films as potential biomaterials with improved mechanical and hydration performances compared to single component formulations. Films were made by the solvent casting method, with or without glycerin and/or PEG1500 as plasticizers, resulting in a total of eight formulations. All films were characterized by their physico-chemical characteristics and their mechanical and hydration features. A full factorial design was also used to statistically assess the effect of HC concentration, type and concentration of plasticizers and their possible interactions on mechanical and swelling behaviors. Solid state characterization confirmed the hybrid nature of the films, with suggested electrostatic interactions between Cs and HC. Mechanical and swelling properties, along with the analysis of the experimental design, allowed the identification of formulations containing high HC concentration (2% w/v) and glycerin or glycerin/PEG1500 as more suitable candidates for skin wound treatment. Finally, viability assay of immortalized human keratinocytes (HaCaT) showed no statistical differences in cell survival compared to the complete culture medium, suggesting their potential as a promising tool for biomedical applications. Full article

(This article belongs to the Special Issue Natural Product-Based Biomaterials for Advanced Wound Dressings)

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14 pages, 4002 KiB

Open AccessEditor’s ChoiceArticle

Water-Soluble Quaternary and Protonable Basic Chitotriazolans: Synthesis by Click Chemistry Conversion of Chitosan Azides and Investigation of Antibacterial Activity

by Sankar Rathinam, Romano Magdadaro, Martha Á. Hjálmarsdóttir and Már Másson

J. Funct. Biomater. 2024, 15(3), 63; https://doi.org/10.3390/jfb15030063 - 5 Mar 2024

Viewed by 1449

Abstract

The azide transfer reaction and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) can be used to convert the amino groups in chitosan to triazole 1,2,3-moieties. The resulting polymer has been named chitotriazolan. This synthesis was performed with six different quaternary ammonium alkynes and three amine alkynes [...] Read more.

The azide transfer reaction and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) can be used to convert the amino groups in chitosan to triazole 1,2,3-moieties. The resulting polymer has been named chitotriazolan. This synthesis was performed with six different quaternary ammonium alkynes and three amine alkynes to obtain a series of nine water-soluble chitotriazolan derivatives. The structure and complete conversion of the azide were confirmed by FT-IR and proton NMR spectroscopy. The derivatives were investigated for antibacterial activity against S. aureus, E. faecalis, E. coli, and P. aeruginosa. The activity of the quaternized chitotriazolan derivatives varied depending on the structure of the quaternary moiety and the species of bacteria. The basic protonable derivatives were less active or inactive against the bacteria. Full article

(This article belongs to the Special Issue Biomedical Applications of Chitin and Chitosan-II)

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11 pages, 2697 KiB

Open AccessEditor’s ChoiceArticle

Injectable Micro-Hydrogel for DNA Delivery: A Promising Therapeutic Platform

by Sunghyun Moon and Jong Bum Lee

J. Funct. Biomater. 2024, 15(3), 59; https://doi.org/10.3390/jfb15030059 - 1 Mar 2024

Viewed by 1615

Abstract

Utilizing the immune system as a strategy for disease prevention and treatment is promising, especially with dendritic cells (DCs) playing a central role in adaptive immune responses. The unique properties of DCs drive interest in developing materials for cell-based therapy and immune modulation. [...] Read more.

Utilizing the immune system as a strategy for disease prevention and treatment is promising, especially with dendritic cells (DCs) playing a central role in adaptive immune responses. The unique properties of DCs drive interest in developing materials for cell-based therapy and immune modulation. Injectable systems require syringe-compatible scaffolds, while hydrogels, like alginate, known for their programmability and biocompatibility, offer a versatile platform for immune medicine enhancement through easy preparation and room-temperature cross-linking. In this study, we synthesized alginate balls loaded with DCs or cytosine–phosphorothioate–guanine deoxyribonucleotide (CpG DNA) microparticles, aiming for long-term immune cell culture with potential immune stimulation effects. Encapsulated DCs exhibited proliferation within the alginate balls for up to 7 days, and CpG MPs were uniformly dispersed, which can facilitate uptake by DCs. This was supported by the result that DCs effectively phagocytosed CpG microparticles in a 2D environment. After the uptake of CpG MPs, the alginate balls with CpG-MP-uptaken DCs were synthesized successfully. The injectable properties of the alginate balls were easily modulated by adjusting the syringe needle gauges. This innovative strategy holds substantial promise for advancing medical treatments, offering effective and comfortable solutions for controlled immune modulation. Full article

(This article belongs to the Special Issue Injectable and Biodegradable Hydrogels for Biomedical Applications)

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12 pages, 2742 KiB

Open AccessEditor’s ChoiceArticle

Polycarbonate-Based Copolymer Micelles as Biodegradable Carriers of Anticancer Podophyllotoxin or Juniper Extracts

by Radostina G. Kalinova, Ivaylo V. Dimitrov, Diana I. Ivanova, Yana E. Ilieva, Alexander N. Tashev, Maya M. Zaharieva, George Angelov and Hristo M. Najdenski

J. Funct. Biomater. 2024, 15(3), 53; https://doi.org/10.3390/jfb15030053 - 21 Feb 2024

Cited by 1 | Viewed by 1740

Abstract

Podophyllotoxin (PPT) is used in the industrial production of efficient anticancer, antiviral and other drugs. Sinopodophyllum hexandrum or Podophyllum peltatum are natural sources of PPT, but at present they are considered as endangered species. Their PPT content is variable, depending on the growing [...] Read more.

Podophyllotoxin (PPT) is used in the industrial production of efficient anticancer, antiviral and other drugs. Sinopodophyllum hexandrum or Podophyllum peltatum are natural sources of PPT, but at present they are considered as endangered species. Their PPT content is variable, depending on the growing conditions. Searching for new sources of PPT, some representatives of the genus Juniperus were found to exhibit efficient PPT biosynthesis. However, PPT is highly toxic and poorly soluble in water compound, which limits its clinical applications. In this connection, amphiphilic polymer micelles are considered to be suitable PPT carriers, aimed at increase in water solubility and decrease in toxicity. The present research deals with the evaluation of MPEG–polycarbonate block copolymer micelles loaded with PPT or juniper extracts. The active component-loaded polymer nanocarriers were characterized by dynamic and electrophoretic light scattering, as well as by transmission electron microscopy. The active component loading efficiency and loading capacity were also determined. Highly efficient antiproliferative activity of the loaded micelles was determined in a panel of cancer cell lines. The obtained amphiphilic nanocarriers, loaded with PPT-containing bioactive components, have application in future in vivo preclinical trials of their pharmacokinetics and pharmacodynamics as potential therapeutical agents in the prospective nanomedicine. Full article

(This article belongs to the Special Issue Synthetic Polymers for the Delivery of Vaccines and Therapeutics)

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24 pages, 19800 KiB

Open AccessEditor’s ChoiceArticle

Advanced Ti–Nb–Ta Alloys for Bone Implants with Improved Functionality

by Jan-Oliver Sass, Marie-Luise Sellin, Elisa Kauertz, Jan Johannsen, Markus Weinmann, Melanie Stenzel, Marcus Frank, Danny Vogel, Rainer Bader and Anika Jonitz-Heincke

J. Funct. Biomater. 2024, 15(2), 46; https://doi.org/10.3390/jfb15020046 - 17 Feb 2024

Cited by 2 | Viewed by 1820

Abstract

The additive manufacturing of titanium–niobium–tantalum alloys with nominal chemical compositions Ti–xNb–6Ta (x = 20, 27, 35) by means of laser beam powder bed fusion is reported, and their potential as implant materials is elaborated by mechanical and biological characterization. The properties of dense [...] Read more.

The additive manufacturing of titanium–niobium–tantalum alloys with nominal chemical compositions Ti–xNb–6Ta (x = 20, 27, 35) by means of laser beam powder bed fusion is reported, and their potential as implant materials is elaborated by mechanical and biological characterization. The properties of dense specimens manufactured in different build orientations and of open porous Ti–20Nb–6Ta specimens are evaluated. Compression tests indicate that strength and elasticity are influenced by the chemical composition and build orientation. The minimum elasticity is always observed in the 90° orientation. It is lowest for Ti–20Nb–6Ta (43.2 ± 2.7 GPa) and can be further reduced to 8.1 ± 1.0 GPa for open porous specimens (p < 0.001). Furthermore, human osteoblasts are cultivated for 7 and 14 days on as-printed specimens and their biological response is compared to that of Ti–6Al–4V. Build orientation and cultivation time significantly affect the gene expression profile of osteogenic differentiation markers. Incomplete cell spreading is observed in specimens manufactured in 0° build orientation, whereas widely stretched cells are observed in 90° build orientation, i.e., parallel to the build direction. Compared to Ti–6Al–4V, Ti–Nb–Ta specimens promote improved osteogenesis and reduce the induction of inflammation. Accordingly, Ti–xNb–6Ta alloys have favorable mechanical and biological properties with great potential for application in orthopedic implants. Full article

(This article belongs to the Special Issue Metallic Biomaterials for Medical Applications)

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14 pages, 2120 KiB

Open AccessEditor’s ChoiceArticle

Surface Modification Strategies for Chrysin-Loaded Iron Oxide Nanoparticles to Boost Their Anti-Tumor Efficacy in Human Colon Carcinoma Cells

by Aynura Karimova, Sabina Hajizada, Habiba Shirinova, Sevinj Nuriyeva, Lala Gahramanli, Mohammed M. Yusuf, Stefano Bellucci, Christoph Reissfelder and Vugar Yagublu

J. Funct. Biomater. 2024, 15(2), 43; https://doi.org/10.3390/jfb15020043 - 13 Feb 2024

Cited by 2 | Viewed by 2613

Abstract

Enhancing nanoparticles’ anti-cancer capabilities as drug carriers requires the careful adjustment of formulation parameters, including loading efficiency, drug/carrier ratio, and synthesis method. Small adjustments to these parameters can significantly influence the drug-loading efficiency of nanoparticles. Our study explored how chitosan and polyethylene glycol [...] Read more.

Enhancing nanoparticles’ anti-cancer capabilities as drug carriers requires the careful adjustment of formulation parameters, including loading efficiency, drug/carrier ratio, and synthesis method. Small adjustments to these parameters can significantly influence the drug-loading efficiency of nanoparticles. Our study explored how chitosan and polyethylene glycol (PEG) coatings affect the structural properties, drug-loading efficiency, and anti-cancer efficacy of Fe₃O₄ nanoparticles (NPs). The loading efficiency of the NPs was determined using FTIR spectrometry and XRD. The quantity of chrysin incorporated into the coated NPs was examined using UV–Vis spectrometry. The effect of the NPs on cell viability and apoptosis was determined by employing the HCT 116 human colon carcinoma cell line. We showed that a two-fold increase in drug concentration did not impact the loading efficiency of Fe₃O₄ NPs coated with PEG. However, there was a 33 Å difference in the crystallite sizes obtained from chitosan-coated Fe₃O₄ NPs and drug concentrations of 1:0.5 and 1:2, resulting in decreased system stability. In conclusion, PEG coating exhibited a higher loading efficiency of Fe₃O₄ NPs compared to chitosan, resulting in enhanced anti-tumor effects. Furthermore, variations in the loaded amount of chrysin did not impact the crystallinity of PEG-coated NPs, emphasizing the stability and regularity of the system. Full article

(This article belongs to the Special Issue Nanoparticles and Nanocompounds for Cancer Therapy)

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17 pages, 10665 KiB

Open AccessEditor’s ChoiceArticle

Femtosecond Laser Irradiation to Zirconia Prior to Calcium Phosphate Coating Enhances Osteointegration of Zirconia in Rabbits

by Hirotaka Mutsuzaki, Hidehiko Yashiro, Masayuki Kakehata, Ayako Oyane and Atsuo Ito

J. Funct. Biomater. 2024, 15(2), 42; https://doi.org/10.3390/jfb15020042 - 11 Feb 2024

Viewed by 4674

Abstract

Calcium phosphate (CaP) coating of zirconia and zirconia-based implants is challenging, due to their chemical instability and susceptibility to thermal and mechanical impacts. A 3 mol% yttrium-stabilized tetragonal zirconia polycrystal was subjected to femtosecond laser (FsL) irradiation to form micro- and submicron surface [...] Read more.

Calcium phosphate (CaP) coating of zirconia and zirconia-based implants is challenging, due to their chemical instability and susceptibility to thermal and mechanical impacts. A 3 mol% yttrium-stabilized tetragonal zirconia polycrystal was subjected to femtosecond laser (FsL) irradiation to form micro- and submicron surface architectures, prior to CaP coating using pulsed laser deposition (PLD) and low-temperature solution processing. Untreated zirconia, CaP-coated zirconia, and FsL-irradiated and CaP-coated zirconia were implanted in proximal tibial metaphyses of male Japanese white rabbits for four weeks. Radiographical analysis, push-out test, alizarin red staining, and histomorphometric analysis demonstrated a much improved bone-bonding ability of FsL-irradiated and CaP-coated zirconia over CaP-coated zirconia without FsL irradiation and untreated zirconia. The failure strength of the FsL-irradiated and CaP-coated zirconia in the push−out test was 6.2–13.1-times higher than that of the CaP-coated zirconia without FsL irradiation and untreated zirconia. Moreover, the adhesion strength between the bone and FsL-irradiated and CaP-coated zirconia was as high as that inducing host bone fracture in the push-out tests. The increased bone-bonding ability was attributed to the micro-/submicron surface architectures that enhanced osteoblastic differentiation and mechanical interlocking, leading to improved osteointegration. FsL irradiation followed by CaP coating could be useful for improving the osteointegration of cement-less zirconia-based joints and zirconia dental implants. Full article

(This article belongs to the Special Issue Scaffolds and Implants for Bone Regeneration)

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11 pages, 1386 KiB

Open AccessEditor’s ChoiceArticle

Superfluorinated, Highly Water-Soluble Polyphosphazenes as Potential ¹⁹F Magnetic Resonance Imaging (MRI) Contrast Agents

by Paul Strasser, Verena Schinegger, Joachim Friske, Oliver Brüggemann, Thomas H. Helbich, Ian Teasdale and Irena Pashkunova-Martic

J. Funct. Biomater. 2024, 15(2), 40; https://doi.org/10.3390/jfb15020040 - 10 Feb 2024

Viewed by 1530

Abstract

“Hot spot” ¹⁹F magnetic resonance imaging (MRI) has garnered significant attention recently for its ability to image various disease markers quantitatively. Unlike conventional gadolinium-based MRI contrast agents, which rely on proton signal modulation, ¹⁹F-MRI’s direct detection has a unique advantage in [...] Read more.

“Hot spot” ¹⁹F magnetic resonance imaging (MRI) has garnered significant attention recently for its ability to image various disease markers quantitatively. Unlike conventional gadolinium-based MRI contrast agents, which rely on proton signal modulation, ¹⁹F-MRI’s direct detection has a unique advantage in vivo, as the human body exhibits a negligible background ¹⁹F-signal. However, existing perfluorocarbon (PFC) or PFC-based contrast materials suffer from several limitations, including low longitudinal relaxation rates and relatively low imaging efficiency. Hence, we designed a macromolecular contrast agent featuring a high number of magnetically equivalent ¹⁹F-nuclei in a single macromolecule, adequate fluorine nucleus mobility, and excellent water solubility. This design utilizes superfluorinated polyphosphazene (PPz) polymers as the ¹⁹F-source; these are modified with sodium mercaptoethanesulfonate (MESNa) to achieve water solubility exceeding 360 mg/mL, which is a similar solubility to that of sodium chloride. We observed substantial signal enhancement in MRI with these novel macromolecular carriers compared to non-enhanced surroundings and aqueous trifluoroacetic acid (TFA) used as a positive control. In conclusion, these novel water-soluble macromolecular carriers represent a promising platform for future MRI contrast agents. Full article

(This article belongs to the Special Issue Synthetic Polymers for the Delivery of Vaccines and Therapeutics)

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23 pages, 26500 KiB

Open AccessEditor’s ChoiceArticle

Fretting and Fretting Corrosion Behavior of Additively Manufactured Ti-6Al-4V and Ti-Nb-Zr Alloys in Air and Physiological Solutions

by Annsley O. Mace, Michael A. Kurtz and Jeremy L. Gilbert

J. Funct. Biomater. 2024, 15(2), 38; https://doi.org/10.3390/jfb15020038 - 5 Feb 2024

Viewed by 1858

Abstract

Additive manufacturing (AM) of orthopedic implants has increased in recent years, providing benefits to surgeons, patients, and implant companies. Both traditional and new titanium alloys are under consideration for AM-manufactured implants. However, concerns remain about their wear and corrosion (tribocorrosion) performance. In this [...] Read more.

Additive manufacturing (AM) of orthopedic implants has increased in recent years, providing benefits to surgeons, patients, and implant companies. Both traditional and new titanium alloys are under consideration for AM-manufactured implants. However, concerns remain about their wear and corrosion (tribocorrosion) performance. In this study, the effects of fretting corrosion were investigated on AM Ti-29Nb-21Zr (pre-alloyed and admixed) and AM Ti-6Al-4V with 1% nano yttria-stabilized zirconia (nYSZ). Low cycle (100 cycles, 3 Hz, 100 mN) fretting and fretting corrosion (potentiostatic, 0 V vs. Ag/AgCl) methods were used to compare these AM alloys to traditionally manufactured AM Ti-6Al-4V. Alloy and admixture surfaces were subjected to (1) fretting in the air (i.e., small-scale reciprocal sliding) and (2) fretting corrosion in phosphate-buffered saline (PBS) using a single diamond asperity (17 µm radius). Wear track depth measurements, fretting currents and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) analysis of oxide debris revealed that pre-alloyed AM Ti-29Nb-21Zr generally had greater wear depths after 100 cycles (4.67 +/− 0.55 µm dry and 5.78 +/− 0.83 µm in solution) and higher fretting currents (0.58 +/− 0.07 µA). A correlation (R² = 0.67) was found between wear depth and the average fretting currents with different alloys located in different regions of the relationship. No statistically significant differences were observed in wear depth between in-air and in-PBS tests. However, significantly higher amounts of oxygen (measured by oxygen weight % by EDS analysis of the debris) were embedded within the wear track for tests performed in PBS compared to air for all samples except the ad-mixed Ti-29Nb-21Zr (p = 0.21). For traditional and AM Ti-6Al-4V, the wear track depths (dry fretting: 2.90 +/− 0.32 µm vs. 2.51 +/− 0.51 μm, respectively; fretting corrosion: 2.09 +/− 0.59 μm vs. 1.16 +/− 0.79 μm, respectively) and fretting current measurements (0.37 +/− 0.05 μA vs. 0.34 +/− 0.05 μA, respectively) showed no significant differences. The dominant wear deformation process was plastic deformation followed by cyclic extrusion of plate-like wear debris at the end of the stroke, resulting in ribbon-like extruded material for all alloys. While previous work documented improved corrosion resistance of Ti-29Nb-21Zr in simulated inflammatory solutions over Ti-6Al-4V, this work does not show similar improvements in the relative fretting corrosion resistance of these alloys compared to Ti-6Al-4V. Full article

(This article belongs to the Special Issue Titanium-Based Implants: Advances in Materials and Applications)

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19 pages, 7431 KiB

Open AccessEditor’s ChoiceArticle

Multifunctional ZnO@DOX/ICG-LMHP Nanoparticles for Synergistic Multimodal Antitumor Activity

by Zhuoyue Li, Jingru Wang, Junwei Liu, Jianming Yu, Jingwen Wang, Hui Wang, Qingchao Wei, Man Liu, Meiqi Xu, Zhenhan Feng, Ting Zhong and Xuan Zhang

J. Funct. Biomater. 2024, 15(2), 35; https://doi.org/10.3390/jfb15020035 - 30 Jan 2024

Cited by 3 | Viewed by 1960

Abstract

Multifunctional nanoparticles are of significant importance for synergistic multimodal antitumor activity. Herein, zinc oxide (ZnO) was used as pH-sensitive nanoparticles for loading the chemotherapy agent doxorubicin (DOX) and the photosensitizer agent indocyanine green (ICG), and biocompatible low-molecular-weight heparin (LMHP) was used as the [...] Read more.

Multifunctional nanoparticles are of significant importance for synergistic multimodal antitumor activity. Herein, zinc oxide (ZnO) was used as pH-sensitive nanoparticles for loading the chemotherapy agent doxorubicin (DOX) and the photosensitizer agent indocyanine green (ICG), and biocompatible low-molecular-weight heparin (LMHP) was used as the gatekeepers for synergistic photothermal therapy/photodynamic therapy/chemotherapy/immunotherapy. ZnO was decomposed into cytotoxic Zn²⁺ ions, leading to a tumor-specific release of ICG and DOX. ZnO simultaneously produced oxygen (O₂) and reactive oxygen species (ROS) for photodynamic therapy (PDT). The released ICG under laser irradiation produced ROS for PDT and raised the tumor temperature for photothermal therapy (PTT). The released DOX directly caused tumor cell death for chemotherapy. Both DOX and ICG also induced immunogenic cell death (ICD) for immunotherapy. The in vivo and in vitro results presented a superior inhibition of tumor progression, metastasis and recurrence. Therefore, this study could provide an efficient approach for designing multifunctional nanoparticles for synergistic multimodal antitumor therapy. Full article

(This article belongs to the Special Issue Nanostructured Materials/Biomaterials for Healthcare Applications)

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35 pages, 988 KiB

Open AccessEditor’s ChoiceReview

The Use of Functional Biomaterials in Aesthetic and Functional Restoration in Orbital Surgery

by Kevin Y. Wu, Jamie K. Fujioka, Patrick Daigle and Simon D. Tran

J. Funct. Biomater. 2024, 15(2), 33; https://doi.org/10.3390/jfb15020033 - 29 Jan 2024

Viewed by 1974

Abstract

The integration of functional biomaterials in oculoplastic and orbital surgery is a pivotal area where material science and clinical practice converge. This review, encompassing primary research from 2015 to 2023, delves into the use of biomaterials in two key areas: the reconstruction of [...] Read more.

The integration of functional biomaterials in oculoplastic and orbital surgery is a pivotal area where material science and clinical practice converge. This review, encompassing primary research from 2015 to 2023, delves into the use of biomaterials in two key areas: the reconstruction of orbital floor fractures and the development of implants and prostheses for anophthalmic sockets post-eye removal. The discussion begins with an analysis of orbital floor injuries, including their pathophysiology and treatment modalities. It is noted that titanium mesh remains the gold standard for orbital floor repair due to its effectiveness. The review then examines the array of materials used for orbital implants and prostheses, highlighting the dependence on surgeon preference and experience, as there are currently no definitive guidelines. While recent innovations in biomaterials show promise, the review underscores the need for more clinical data before these new materials can be widely adopted in clinical settings. The review advocates for an interdisciplinary approach in orbital surgery, emphasizing patient-centered care and the potential of biomaterials to significantly enhance patient outcomes. Full article

(This article belongs to the Special Issue Women in Science: Functional Biomaterials)

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24 pages, 3982 KiB

Open AccessEditor’s ChoiceReview

Biomaterials Functionalized with Inflammasome Inhibitors—Premises and Perspectives

by Norina Vinţeler, Claudia Nicoleta Feurdean, Regina Petkes, Reka Barabas, Bianca Adina Boşca, Alexandrina Muntean, Dana Feștilă and Aranka Ilea

J. Funct. Biomater. 2024, 15(2), 32; https://doi.org/10.3390/jfb15020032 - 28 Jan 2024

Cited by 1 | Viewed by 2183

Abstract

This review aimed at searching literature for data regarding the inflammasomes’ involvement in the pathogenesis of oral diseases (mainly periodontitis) and general pathologies, including approaches to control inflammasome-related pathogenic mechanisms. The inflammasomes are part of the innate immune response that activates inflammatory caspases [...] Read more.

This review aimed at searching literature for data regarding the inflammasomes’ involvement in the pathogenesis of oral diseases (mainly periodontitis) and general pathologies, including approaches to control inflammasome-related pathogenic mechanisms. The inflammasomes are part of the innate immune response that activates inflammatory caspases by canonical and noncanonical pathways, to control the activity of Gasdermin D. Once an inflammasome is activated, pro-inflammatory cytokines, such as interleukins, are released. Thus, inflammasomes are involved in inflammatory, autoimmune and autoinflammatory diseases. The review also investigated novel therapies based on the use of phytochemicals and pharmaceutical substances for inhibiting inflammasome activity. Pharmaceutical substances can control the inflammasomes by three mechanisms: inhibiting the intracellular signaling pathways (Allopurinol and SS-31), blocking inflammasome components (VX-765, Emricasan and VX-740), and inhibiting cytokines mediated by the inflammasomes (Canakinumab, Anakinra and Rilonacept). Moreover, phytochemicals inhibit the inflammasomes by neutralizing reactive oxygen species. Biomaterials functionalized by the adsorption of therapeutic agents onto different nanomaterials could represent future research directions to facilitate multimodal and sequential treatment in oral pathologies. Full article

(This article belongs to the Section Biomaterials and Devices for Healthcare Applications)

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11 pages, 2244 KiB

Open AccessEditor’s ChoiceArticle

Effect of Silicon Carbide Fiber Length on the Flexural Strength and Flexural Modulus of Short Silicon Carbide Fiber-Reinforced Resin

by Norimasa Taka, Yujin Aoyagi, Keito Miida, Mitsugu Kanatani and Hiroshi Ogawa

J. Funct. Biomater. 2024, 15(2), 30; https://doi.org/10.3390/jfb15020030 - 26 Jan 2024

Viewed by 1527

Abstract

Silicon carbide fibers have superior flexural properties and chemical stability compared to glass fibers. We investigated the flexural strength and modulus of an experimental, short silicon carbide fiber-reinforced resin. Short silicon carbide fibers with lengths of ~0.5, 1, 2, and 3 mm were [...] Read more.

Silicon carbide fibers have superior flexural properties and chemical stability compared to glass fibers. We investigated the flexural strength and modulus of an experimental, short silicon carbide fiber-reinforced resin. Short silicon carbide fibers with lengths of ~0.5, 1, 2, and 3 mm were prepared and silanized. Urethane dimethacrylate and triethylene glycol dimethacrylate were mixed at a 70:30 wt% ratio and used as the matrix resins. Each length of short silicon carbide fibers and the matrix resin were combined using a mixing machine and then used for specimen preparation. The three-point bending test conditions were in accordance with ISO 4049:2009. The fracture surfaces of the specimens after the three-point bending test were observed using secondary electron images. The data were statistically analyzed with a one-way analysis of variance and Tukey’s HSD test (α = 0.05). The flexural strength and modulus of the specimens containing 2 mm or 3 mm silicon carbide fibers were significantly higher than the other specimens. The river pattern was observed more clearly in specimens containing shorter silicon carbide fibers, although this pattern was observed in all specimens. Full article

(This article belongs to the Section Dental Biomaterials)

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15 pages, 6823 KiB

Open AccessEditor’s ChoiceArticle

Surface-Mediated Modulation of Different Biological Responses on Anatase-Coated Titanium

by Leila Mohammadnejad, Antonia Theurer, Julia Alber, Barbara Illing, Evi Kimmerle-Mueller, Jacob Schultheiss, Stefanie Krajewski and Frank Rupp

J. Funct. Biomater. 2024, 15(2), 29; https://doi.org/10.3390/jfb15020029 - 25 Jan 2024

Viewed by 1706

Abstract

Various surface modification strategies are being developed to endow dental titanium implant surfaces with micro- and nano-structures to improve their biocompatibility, and first of all their osseointegration. These modifications have the potential to address clinical concerns by stimulating different biological processes. This study [...] Read more.

Various surface modification strategies are being developed to endow dental titanium implant surfaces with micro- and nano-structures to improve their biocompatibility, and first of all their osseointegration. These modifications have the potential to address clinical concerns by stimulating different biological processes. This study aims to evaluate the biological responses of ananatase-modified blasted/etched titanium (SLA-anatase) surfaces compared to blasted/acid etched (SLA) and machined titanium surfaces. Using unipolar pulsed direct current (DC) sputtering, a nanocrystalline anatase layer was fabricated. In vitro experiments have shown that SLA-anatase discs can effectively promote osteoblast adhesion and proliferation, which are regarded as important features of a successful dental implant with bone contact. Furthermore, anatase surface modification has been shown to partially enhance osteoblast mineralization in vitro, while not significantly affecting bacterial colonization. Consequently, the recently created anatase coating holds significant potential as a promising candidate for future advancements in dental implant surface modification for improving the initial stages of osseointegration. Full article

(This article belongs to the Section Dental Biomaterials)

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12 pages, 3455 KiB

Open AccessEditor’s ChoiceArticle

Mechanical Properties and Corrosion Rate of ZnAg3 as a Novel Bioabsorbable Material for Osteosynthesis

by Maria Roesner, Sergej Zankovic, Adalbert Kovacs, Moritz Benner, Roland Barkhoff and Michael Seidenstuecker

J. Funct. Biomater. 2024, 15(2), 28; https://doi.org/10.3390/jfb15020028 - 25 Jan 2024

Viewed by 1772

Abstract

Osteosynthesis in fracture treatment typically uses hardware that remains in the patient’s body, which brings a permanent risk of negative side effects such as foreign body reactions or chronic inflammation. Bioabsorbable materials, however, can degrade and slowly be replaced by autologous bone tissue. [...] Read more.

Osteosynthesis in fracture treatment typically uses hardware that remains in the patient’s body, which brings a permanent risk of negative side effects such as foreign body reactions or chronic inflammation. Bioabsorbable materials, however, can degrade and slowly be replaced by autologous bone tissue. A suitable material is requested to offer great biocompatibility alongside excellent mechanical properties and a reasonable corrosion rate. Zinc–silver alloys provide these characteristics, which makes them a promising candidate for research. This study investigated the aptitude as a bioabsorbable implant of a novel zinc–silver alloy containing 3.3 wt% silver (ZnAg3). Here, the tensile strength as well as the corrosion rate in PBS solution (phosphate buffered solution) of ZnAg3 were assessed. Furthermore, shear tests, including fatigue and quasi-static testing, were conducted with ZnAg3 and magnesium pins (MAGNEZIX^®, Syntellix AG, Hannover, Germany), which are already in clinical use. The detected corrosion rate of 0.10 mm/year for ZnAg3 was within the proposed range for bioabsorbable implants. With a tensile strength of 237.5 ± 2.12 MPa and a shear strength of 144.8 ± 13.2 N, ZnAg3 satisfied the mechanical requirements for bioabsorbable implants. The fatigue testing did not show any significant difference between ZnAg3 and magnesium pins, whereas both materials withstood the cyclic loading. Thus, the results support the assumption that ZnAg3 is qualified for further investigation. Full article

(This article belongs to the Special Issue Advances in Bone Substitute Biomaterials)

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17 pages, 3429 KiB

Open AccessEditor’s ChoiceArticle

Engineering Degradation Rate of Polyphosphazene-Based Layer-by-Layer Polymer Coatings

by Jordan Brito, Junho Moon, Raman Hlushko, Aliaksei Aliakseyeu, Alexander K. Andrianov and Svetlana A. Sukhishvili

J. Funct. Biomater. 2024, 15(2), 26; https://doi.org/10.3390/jfb15020026 - 23 Jan 2024

Viewed by 1802

Abstract

Degradable layer-by-layer (LbL) polymeric coatings have distinct advantages over traditional biomedical coatings due to their precision of assembly, versatile inclusion of bioactive molecules, and conformality to the complex architectures of implantable devices. However, controlling the degradation rate while achieving biocompatibility has remained a [...] Read more.

Degradable layer-by-layer (LbL) polymeric coatings have distinct advantages over traditional biomedical coatings due to their precision of assembly, versatile inclusion of bioactive molecules, and conformality to the complex architectures of implantable devices. However, controlling the degradation rate while achieving biocompatibility has remained a challenge. This work employs polyphosphazenes as promising candidates for film assembly due to their inherent biocompatibility, tunability of chemical composition, and the buffering capability of degradation products. The degradation of pyrrolidone-functionalized polyphosphazenes was monitored in solution, complexes and LbL coatings (with tannic acid), providing the first to our knowledge comparison of solution-state degradation to solid-state LbL degradation. In all cases, the rate of degradation accelerated in acidic conditions. Importantly, the tunability of the degradation rate of polyphosphazene-based LbL films was achieved by varying film assembly conditions. Specifically, by slightly increasing the ionization of tannic acid (near neutral pH), we introduce electrostatic “defects” to the hydrogen-bonded pairs that accelerate film degradation. Finally, we show that replacing the pyrrolidone side group with a carboxylic acid moiety greatly reduces the degradation rate of the LbL coatings. In practical applications, these coatings have the versatility to serve as biocompatible platforms for various biomedical applications and controlled release systems. Full article

(This article belongs to the Section Biomaterials for Drug Delivery)

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13 pages, 4732 KiB

Open AccessEditor’s ChoiceArticle

Chemical and Ultrastructural Characterization of Dentin Treated with Remineralizing Dentifrices

by Dimitra Athanasiadou, Denise Eymael, Beshr Hajhamid, Karina M. M. Carneiro and Anuradha Prakki

J. Funct. Biomater. 2024, 15(1), 25; https://doi.org/10.3390/jfb15010025 - 16 Jan 2024

Viewed by 1938

Abstract

The aim of this study is to investigate dentin chemical and ultrastructural changes upon exposure to remineralizing dentifrices. Dentin disks were obtained from permanent human molars and treated for 7 days with the dentifrices: (1) C group—control (no dentifrice); (2) S group—Sensodyne Repair [...] Read more.

The aim of this study is to investigate dentin chemical and ultrastructural changes upon exposure to remineralizing dentifrices. Dentin disks were obtained from permanent human molars and treated for 7 days with the dentifrices: (1) C group—control (no dentifrice); (2) S group—Sensodyne Repair & Protect; (3) D group—Dentalclean Daily Regenerating Gel; and (4) DB group—D group + Dentalclean regenerating booster. Afterwards, samples were submitted to an additional 7 days of toothbrushing associated with daily acidic challenge. Samples were imaged and analyzed (days 1, 7, and 14) for Young’s modulus by atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). SEM and AFM revealed precipitate deposition on dentin surfaces in groups S, D, and DB, formed as early as day 1. Surface elemental analysis showed a Si increase on all brushed surfaces. Similar surface morphology was maintained after the acidic challenge period. Bright-field TEM/SAED revealed the formation of nanocrystalline hydroxyapatite inside the dentin tubules of groups S, D, and DB after day 7. Group C presented a gradual reduction of Young’s modulus from days-1–14, whereas all remaining groups had increased values. All evaluated dentifrices led to successful formation of hydroxyapatite and increased dentin stiffness. Full article

(This article belongs to the Special Issue Surface Analyses of Dental Biomaterials, Physicochemical and Mechanical Properties)

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16 pages, 5352 KiB

Open AccessEditor’s ChoiceArticle

Development of a Nanoparticle System for Controlled Release in Bioprinted Respiratory Scaffolds

by Amanda Zimmerling, Christina Sunil, Yan Zhou and Xiongbiao Chen

J. Funct. Biomater. 2024, 15(1), 20; https://doi.org/10.3390/jfb15010020 - 12 Jan 2024

Cited by 1 | Viewed by 2624

Abstract

The use of nanoparticle systems for the controlled release of growth factors is a promising approach to mimicking of the biochemical environment of native tissues in tissue engineering. However, sustaining growth factor release inside an appropriate therapeutic window is a challenge, particularly in [...] Read more.

The use of nanoparticle systems for the controlled release of growth factors is a promising approach to mimicking of the biochemical environment of native tissues in tissue engineering. However, sustaining growth factor release inside an appropriate therapeutic window is a challenge, particularly in bioprinted scaffolds. In this study, a chitosan-coated alginate-based nanoparticle system loaded with hepatocyte growth factor was developed and then incorporated into bioprinted scaffolds. The release kinetics were investigated with a focus on identifying the impact of the chitosan coating and culture conditions. Our results demonstrated that the chitosan coating decreased the release rate and lessened the initial burst release, while culturing in dynamic conditions had no significant impact compared to static conditions. The nanoparticles were then incorporated into bioinks at various concentrations, and scaffolds with a three-dimensional (3D) structure were bioprinted from the bioinks containing human pulmonary fibroblasts and bronchial epithelial cells to investigate the potential use of a controlled release system in respiratory tissue engineering. It was found that the bioink loaded with a concentration of 4 µg/mL of nanoparticles had better printability compared to other concentrations, while the mechanical stability of the scaffolds was maintained over a 14-day culture period. The examination of the incorporated cells demonstrated a high degree of viability and proliferation with visualization of the beginning of an epithelial barrier layer. Taken together, this study demonstrates that a chitosan-coated alginate-based nanoparticle system allows the sustained release of growth factors in bioprinted respiratory tissue scaffolds. Full article

(This article belongs to the Special Issue Advanced Functional Hydrogels for Tissue Engineering and Regenerative Medicine)

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