Journal of Functional Biomaterials

15 pages, 755 KiB

Open AccessReview

Propolis as an Adjunct in Non-Surgical Periodontal Therapy: Current Clinical Perspectives from a Narrative Review

by Vitolante Pezzella, Alessandro Cuozzo, Leopoldo Mauriello, Alessandro Polizzi, Vincenzo Iorio Siciliano, Luca Ramaglia and Andrea Blasi

J. Funct. Biomater. 2025, 16(7), 265; https://doi.org/10.3390/jfb16070265 - 16 Jul 2025

Abstract

Non-surgical periodontal therapy (NSPT) represents the gold standard in the treatment of periodontitis, but deep periodontal pockets and complex anatomies may reduce its efficacy. Therefore, in order to enhance NSPT outcomes and reduce the need for surgical intervention, several adjunctive therapies have been [...] Read more.

Non-surgical periodontal therapy (NSPT) represents the gold standard in the treatment of periodontitis, but deep periodontal pockets and complex anatomies may reduce its efficacy. Therefore, in order to enhance NSPT outcomes and reduce the need for surgical intervention, several adjunctive therapies have been proposed. Propolis, a natural substance with antimicrobial, anti-inflammatory, and healing properties, has shown promising results in controlling supragingival biofilm. This narrative review aims to assess the clinical efficacy of propolis as an adjunct to NSPT. A comprehensive search on scientific databases was conducted for randomised clinical trials (RCTs) comparing NSPT with and without propolis, or with other adjuncts or placebos. Probing depth (PD) was the primary outcome. Seven RCTs met the inclusion criteria, using different propolis formulations and application protocols. Statistically significant improvements in clinical outcomes were recorded in all analysed studies compared with NSPT alone or placebo, while benefits were less substantial compared with laser therapy and conflicting when compared with chlorhexidine. Thus propolis may be considered a promising adjunctive agent to NSPT, with the potential to improve clinical outcomes of NSPT. Nonetheless, further long-term clinical trials with larger sample size are needed to validate its clinical efficacy and to determine its adverse effects. Full article

(This article belongs to the Section Dental Biomaterials)

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10 pages, 2732 KiB

Open AccessArticle

In-Vitro Assessment of Artificial Tooth Material Wear Behavior Using 3D Wear Analysis

by Sıla Yelekçi, Ayben Şentürk and Funda Akaltan

J. Funct. Biomater. 2025, 16(7), 264; https://doi.org/10.3390/jfb16070264 - 16 Jul 2025

Abstract

Background: Artificial tooth wear impacts prosthesis durability and function; understanding material–antagonist interactions guides clinical choices. Aim: This in-vitro study aimed to assess the wear behavior of isosit and nanohybrid composite resin artificial teeth when opposed to various antagonist materials using 3D volumetric wear [...] Read more.

Background: Artificial tooth wear impacts prosthesis durability and function; understanding material–antagonist interactions guides clinical choices. Aim: This in-vitro study aimed to assess the wear behavior of isosit and nanohybrid composite resin artificial teeth when opposed to various antagonist materials using 3D volumetric wear analysis. Materials and Methods: Sixty specimens (n = 10 per group) were prepared from two artificial tooth materials and assigned to six antagonist combinations: isosit–isosit, isosit–nanohybrid composite, isosit–porcelain, nanohybrid composite–isosit, nanohybrid composite–nanohybrid composite, and nanohybrid composite–porcelain. Specimens were scanned before and after 600,000 chewing cycles using a structured-light 3D scanner. Volumetric wear was calculated by superimposing pre- and post-test scans. Data were analyzed using two-way ANOVA and Tukey’s HSD test (α = 0.05). Results: Porcelain antagonists produced the highest wear values (p < 0.05). No significant difference was found between isosit and nanohybrid antagonists (p > 0.05). Identical material pairings showed less wear, though differences were not statistically significant. Conclusions: Porcelain as an antagonist increased wear risk. Using identical materials bilaterally, such as isosit–isosit or nanohybrid–nanohybrid, may help reduce artificial tooth wear in removable prostheses. Full article

(This article belongs to the Special Issue State of the Art: Biomaterials and Oral Implantology)

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24 pages, 5956 KiB

Open AccessArticle

Effects of Different Surface Treatments and Accelerated Aging on Dental Zirconia—An In Vitro Study

by Mihaela Pantea, Lucian Toma Ciocan, Vlad Gabriel Vasilescu, Georgeta Voicu, Adrian-Ionut Nicoară, Florin Miculescu, Robert Ciocoiu, Ana Maria Cristina Țâncu, Elena Georgiana Banu and Marina Imre

J. Funct. Biomater. 2025, 16(7), 263; https://doi.org/10.3390/jfb16070263 - 16 Jul 2025

Abstract

This in vitro study aimed to compare the effects of various surface treatments and hydrothermal aging on the phase composition, microstructure, and compressive strength of dental zirconia (ZrO₂). Forty-eight zirconia cubes (8 × 8 × 8 mm) were fabricated using CAD/CAM [...] Read more.

This in vitro study aimed to compare the effects of various surface treatments and hydrothermal aging on the phase composition, microstructure, and compressive strength of dental zirconia (ZrO₂). Forty-eight zirconia cubes (8 × 8 × 8 mm) were fabricated using CAD/CAM from two materials: infrastructure zirconia (Group S1) and super-translucent multilayered monolithic zirconia (Group S2). Four samples of each material were analyzed in their pre-sintered state (S1-0, S2-0). The remaining specimens were sintered and assigned to sub-groups based on surface treatment: untreated, sandblasted with 30 µm or 50 µm Al₂O₃, polished, or polished and glazed. Characterization was performed using EDX, SEM, XRD with Rietveld refinement, Raman spectroscopy, and compressive testing before and after accelerated hydrothermal aging, according to EN ISO 13356:2015. EDX revealed a higher yttria content in monolithic zirconia (10.57 wt%) than in infrastructure zirconia (6.51 wt%). SEM images showed minimal changes in polished samples but clear surface damage after sandblasting, which was more pronounced with larger abrasive particles. XRD and Raman confirmed that sandblasting promoted the tetragonal (t-ZrO₂) to monoclinic (m-ZrO₂) phase transformation (t→m), amplified further by hydrothermal aging. The polished groups showed greater phase stability post-aging. Compressive strength decreased in all treated and aged samples, with monolithic zirconia being more affected. Polished samples displayed the best surface quality and structural resilience across both materials. These findings underline the impact of clinical surface treatments on zirconia’s long-term mechanical and structural behavior. Full article

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

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22 pages, 2494 KiB

Open AccessSystematic Review

Reassessing the Use of Membranes in Peri-Implantitis Surgery: A Systematic Review and Meta-Analysis of In Vivo Studies

by Young Joon Cho, Yong Tak Jeong, Hyun Nyun Woo, Hyun Woo Cho, Min Gu Kang, Sung-Min Hwang and Jae-Mok Lee

J. Funct. Biomater. 2025, 16(7), 262; https://doi.org/10.3390/jfb16070262 - 15 Jul 2025

Abstract

Peri-implantitis (PI) presents a growing challenge in implant dentistry, with regenerative surgical approaches often incorporating barrier membranes despite the uncertainty of their clinical value. This systematic review and meta-analysis of in vivo studies aimed to evaluate the efficacy of barrier membranes in the [...] Read more.

Peri-implantitis (PI) presents a growing challenge in implant dentistry, with regenerative surgical approaches often incorporating barrier membranes despite the uncertainty of their clinical value. This systematic review and meta-analysis of in vivo studies aimed to evaluate the efficacy of barrier membranes in the reconstructive surgical treatment of PI. A comprehensive electronic search was performed in PubMed, Scopus, Google Scholar, and the Cochrane Library, covering studies published from 1990 to 2024. The protocol followed PRISMA guidelines and was registered in PROSPERO (CRD42025625417). Eligible studies included in vivo investigations comparing regenerative procedures with and without membrane use, with a minimum follow-up of 6 months and at least 10 implants per study. Risk of bias (RoB) was assessed using the Cochrane RoB tool. The meta-analysis was conducted using a random-effects model and included 15 studies comprising 560 patients. Although not consistently statistically significant, the findings suggested that membrane use may offer enhanced outcomes in terms of probing pocket depth (PPD) reduction and marginal bone level (MLB) gain. The evidence was limited by high clinical heterogeneity, variability in outcome definitions, and short follow-up durations. While membranes are commonly utilized, current evidence does not justify their routine use. Further well-designed, long-term clinical trials are needed to establish specific indications and optimize treatment strategies. Full article

(This article belongs to the Special Issue New Biomaterials in Periodontology and Implantology)

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15 pages, 2606 KiB

Open AccessArticle

A Collagen Membrane Pretreated with Citrate Promotes Collagen Mineralization and Bone Regeneration

by Qi Zhang, Yewen Zhong, Xinlin He and Sui Mai

J. Funct. Biomater. 2025, 16(7), 261; https://doi.org/10.3390/jfb16070261 - 15 Jul 2025

Abstract

Purpose: Collagen membranes with biomimetic mineralization are emerging as promising materials for bone regeneration, owing to their high biocompatibility. In this study, we developed a biogenic collagen membrane by combining citrate (C) pretreatment and carboxymethyl chitosan (CMC)-mediated mineralization and further evaluated its bone [...] Read more.

Purpose: Collagen membranes with biomimetic mineralization are emerging as promising materials for bone regeneration, owing to their high biocompatibility. In this study, we developed a biogenic collagen membrane by combining citrate (C) pretreatment and carboxymethyl chitosan (CMC)-mediated mineralization and further evaluated its bone healing potential. Methods: C-CMC collagen membranes were prepared by lyophilization. The mineral composition and content were tested through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The micromorphology was observed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and scanning probe microscopy (SPM). Physical and mechanical properties, including the swelling rate, porosity, hydrophilicity, tensile strength, Young’s modulus, degradation, and barrier function, were also evaluated. Bone mesenchymal stem cells (BMSCs) were cultured in vitro to observe their behavior. An in vivo critical-size rat calvarial defect model was used to validate the effects of the membrane on bone regeneration. Results: The C-CMC collagen membrane was successfully synthesized as a collagen–hydroxyapatite complex with intrafibrillar mineralization, exhibiting improved mechanical properties and an optimal swelling rate, porosity, hydrophilicity, and degradation rate. Additionally, the C-CMC collagen membrane promoted BMSC proliferation, adhesion, and osteogenesis while preventing epithelial cell infiltration. In vivo experiments indicated that C-CMC collagen membranes significantly stimulated bone regeneration without causing systemic toxicity. Conclusions: Our findings suggest that the C-CMC collagen membrane possesses satisfactory physical and mechanical properties, along with good biocompatibility and efficacy in bone defect regeneration, making it a potential candidate for a bioactive guided bone regeneration membrane in clinical applications. Full article

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

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15 pages, 2730 KiB

Open AccessArticle

The Influence of Insertion Torque on Stress Distribution in Peri-Implant Bones Around Ultra-Short Implants: An FEA Study

by Mario Ceddia, Lorenzo Montesani, Luca Comuzzi, Alessandro Cipollina, Douglas A. Deporter, Natalia Di Pietro and Bartolomeo Trentadue

J. Funct. Biomater. 2025, 16(7), 260; https://doi.org/10.3390/jfb16070260 - 14 Jul 2025

Abstract

Using ultra-short dental implants is a promising alternative to extensive bone grafting procedures for patients with atrophic posterior mandibles and vertical bone loss. However, the amount of insertion torque (IT) applied during implant placement significantly influences stress distribution in the peri-implant bone, which [...] Read more.

Using ultra-short dental implants is a promising alternative to extensive bone grafting procedures for patients with atrophic posterior mandibles and vertical bone loss. However, the amount of insertion torque (IT) applied during implant placement significantly influences stress distribution in the peri-implant bone, which affects implant stability and long-term success. Materials and Methods: This study used finite element analysis (FEA) to examine how different insertion torques (35 N·cm and 75 N·cm) affect stress distribution in cortical and trabecular bone types D2 and D4 surrounding ultra-short implants. Von Mises equivalent stress values were compared with ultimate bone strength thresholds to evaluate the potential for microdamage during insertion. Results: The findings demonstrate that increasing IT from 35 N·cm to 75 N·cm led to a significant increase in peri-implant bone stress. Specifically, cortical bone stress in D4 bone increased from approximately 79 MPa to 142 MPa with higher IT, exceeding physiological limits and elevating the risk of microfractures and bone necrosis. In contrast, lower IT values kept stress within safe limits, ensuring optimal primary stability without damaging the bone. These results underscore the need to strike a balance between achieving sufficient implant stability and avoiding mechanical trauma to the surrounding bone. Conclusions: Accurate control of insertion torque during the placement of ultra-short dental implants is crucial to minimize bone damage and promote optimal osseointegration. Excessive torque, especially in low-density bone, can compromise implant success by inducing excessive stress, thereby increasing the risk of early failure. Full article

(This article belongs to the Section Dental Biomaterials)

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15 pages, 8575 KiB

Open AccessArticle

Chlorogenic Acid–Strontium-Containing Dual-Functional Bioresorbable External Stent Suppresses Venous Graft Restenosis via Hippo-YAP Signaling Pathway

by Ge Zhu, Su Wang, Zhang Liu, Shengji Gu, Feng Chen and Wangfu Zang

J. Funct. Biomater. 2025, 16(7), 259; https://doi.org/10.3390/jfb16070259 - 11 Jul 2025

Abstract

Vein graft restenosis remains a major complication following coronary artery bypass grafting (CABG), mainly due to the abnormal proliferation of vascular smooth muscle cells (VSMCs) and impaired endothelial repair. While external stents (eStents) can provide mechanical support and limit adverse remodeling, traditional metallic [...] Read more.

Vein graft restenosis remains a major complication following coronary artery bypass grafting (CABG), mainly due to the abnormal proliferation of vascular smooth muscle cells (VSMCs) and impaired endothelial repair. While external stents (eStents) can provide mechanical support and limit adverse remodeling, traditional metallic stents are non-degradable and may induce chronic inflammation and fibrosis. In contrast, many bioresorbable materials degrade too quickly or lack mechanical strength. These challenges highlight the need for external stents that combine sufficient mechanical strength with biodegradability to support long-term graft patency. This is the first study that develops a chlorogenic acid–strontium (SrCA)-loaded polycaprolactone bioresorbable eStent that inhibits VSMC proliferation and enhances endothelial repair via Hippo–Yes-associated protein (YAP) signaling, addressing vein graft restenosis post-CABG. Combining mechanical support and biodegradability, it overcomes the limitations of non-degradable stents and rapidly degrading biomaterials, elucidates the potential of natural polyphenol–metal ion complexes in vascular remodeling, and offers an innovative strategy for the prevention of vein graft restenosis. Full article

(This article belongs to the Special Issue The 15th Anniversary of JFB—Functional Biomaterials: Bioactive Properties and Medical Applications)

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22 pages, 8601 KiB

Open AccessArticle

Synthesis of Ag₂O/Ag Nanoparticles Using Puerarin: Characterization, Cytotoxicity, In Ovo Safety Profile, Antioxidant, and Antimicrobial Potential Against Nosocomial Pathogens

by Sergio Liga, Raluca Vodă, Lavinia Lupa, Elena-Alina Moacă, Delia Muntean, Lucian Barbu-Tudoran, Maria Suciu, Vlad Socoliuc and Francisc Péter

J. Funct. Biomater. 2025, 16(7), 258; https://doi.org/10.3390/jfb16070258 - 11 Jul 2025

Abstract

(1) Background: Our study investigates the green synthesis of Ag₂O/Ag nanoparticles using the isoflavone Puerarin as a bioreductor. (2) Methods: The PUE@Ag₂O/Ag nanoparticles were characterized using various techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), electronic [...] Read more.

(1) Background: Our study investigates the green synthesis of Ag₂O/Ag nanoparticles using the isoflavone Puerarin as a bioreductor. (2) Methods: The PUE@Ag₂O/Ag nanoparticles were characterized using various techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), electronic microscopy (TEM, SEM), energy dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS). Biological activities were assessed through antimicrobial testing, cytotoxicity assays on human keratinocytes and melanoma cells, and an in ovo screening using the HET-CAM assay. (3) Results: The formation of crystalline Ag₂O/Ag nanoparticles with sizes below 100 nm was accomplished with Puerarin. Despite their high cytotoxicity at all tested concentrations, the nanoparticles showed antioxidant activity with IC₅₀ 981.5 ± 94.2 μg/mL, antibacterial activity against several clinically relevant nosocomial strains (Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa), and no local irritant effects or inhibition of angiogenesis in the HET-CAM assay. (4) Conclusions: This study provides insights into the synthesis, characterization, and biological profile of PUE@Ag₂O/Ag nanoparticles for potential biomedical applications. Full article

(This article belongs to the Special Issue Nanoparticles and Nanomaterials to Counteract Healthcare-Associated Infections)

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13 pages, 4323 KiB

Open AccessArticle

The Impact of Additive and Subtractive Manufacturing on the Adhesion and Durability of Titanium–Zirconia Restorative Materials

by Omar Alageel, Najm Alfrisany, Abdullah Alshamrani and Omar Alsadon

J. Funct. Biomater. 2025, 16(7), 257; https://doi.org/10.3390/jfb16070257 - 11 Jul 2025

Abstract

This study aimed to investigate the bonding strength and durability of titanium alloys bonded to zirconia-based materials produced using subtractive and additive digital methods. Two titanium alloy groups (N = 20) and two zirconia ceramic groups (N = 60) were fabricated using CAD/CAM [...] Read more.

This study aimed to investigate the bonding strength and durability of titanium alloys bonded to zirconia-based materials produced using subtractive and additive digital methods. Two titanium alloy groups (N = 20) and two zirconia ceramic groups (N = 60) were fabricated using CAD/CAM milling from prefabricated discs (Ti-ML and Zr-ML), and 3D printing via SLM (Ti-3D) and DLP/LCM systems (Zr-3D). The specimens were bonded with dental cement to form four test groups: Zr-ML/Ti-ML, Zr-ML/Ti-3D, Zr-3D/Ti-ML, and Zr-3D/Ti-3D. Half of the specimens in each group underwent thermocycling to assess the effect of aging on bond strength. The density, microhardness, and surface morphology were evaluated, along with the shear bond strength and failure modes of the resin composites. Statistical differences were analyzed using one-way ANOVA and Tukey’s HSD test across all groups. The 3D-printed specimens of both materials exhibited higher microhardness and lower surface roughness than the milled specimens. The shear bond strength (SBS) was the highest in the Ti-ML/Zr-ML combination group before and after thermocycling, which had more cohesive failures, whereas the lowest bond strength was observed in the Ti-3D/Zr-ML group. The adhesion between titanium and zirconia-based materials was the strongest when both were fabricated using subtractive methods, followed by additive and mixed-method combinations. Full article

(This article belongs to the Section Dental Biomaterials)

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15 pages, 2192 KiB

Open AccessArticle

Intermittent Catheters with Integrated Amphiphilic Surfactant Reduce Urethral Microtrauma in an Ex Vivo Model Compared with Polyvinylpyrrolidone-Coated Intermittent Catheters

by Luca Barbieri, Makhara S. Ung, Katherine E. Hill, Ased Ali and Laura A. Smith Callahan

J. Funct. Biomater. 2025, 16(7), 256; https://doi.org/10.3390/jfb16070256 - 10 Jul 2025

Abstract

Intermittent catheterization mitigates urinary retention for over 300,000 people in the US every year, but can cause microtrauma in the urothelium, compromising its barrier function and increasing the risk of pathogen entry, which may affect user health. To reduce adverse effects, intermittent catheters [...] Read more.

Intermittent catheterization mitigates urinary retention for over 300,000 people in the US every year, but can cause microtrauma in the urothelium, compromising its barrier function and increasing the risk of pathogen entry, which may affect user health. To reduce adverse effects, intermittent catheters (ICs) with increased lubricity are used. A common strategy to enhance IC lubricity is to apply a polyvinylpyrrolidone (PVP) coating to ICs; however, this coating can become adhesive upon drying, potentially leading to microtrauma. An alternative approach for lubricity is the migration of integrated amphiphilic surfactant (IAS) within the IC to the surface. The present work examines differences in urethral microtrauma caused by the simulated catheterization of ex vivo porcine urethral tissue using PVP-coated and IAS ICs. Scanning electron microscopy and fluorescence microscopy of the tissue showed the removal of the apical cell layer after contact with the PVP-coated ICs, but not the IAS IC. More extracellular matrices and DNA were observed on the PVP-coated ICs than the IAS IC after tissue contact. Contact angle analysis of the polar and dispersive components of the surface energy demonstrated that the PVP-coated ICs promoted mucoadhesion, while the IAS IC limited mucoadhesion. Overall, the results indicate that IAS ICs cause less microtrauma to urethral tissue than traditional PVP-coated ICs. Full article

(This article belongs to the Collection Feature Papers in Biomaterials for Healthcare Applications)

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36 pages, 2739 KiB

Open AccessReview

Advanced Bioactive Polymers and Materials for Nerve Repair: Strategies and Mechanistic Insights

by Nidhi Puranik, Shraddha Tiwari, Meenakshi Kumari, Shiv Kumar Yadav, Thakur Dhakal and Minseok Song

J. Funct. Biomater. 2025, 16(7), 255; https://doi.org/10.3390/jfb16070255 - 9 Jul 2025

Abstract

Bioactive materials have recently shown potential in nerve repair and regeneration by promoting the growth of new cells, tissue repair, and restoring nerve function. These natural, synthetic, and hybrid materials offer a biomimetic structure, enhance cell attachment, and release bioactive molecules that promote [...] Read more.

Bioactive materials have recently shown potential in nerve repair and regeneration by promoting the growth of new cells, tissue repair, and restoring nerve function. These natural, synthetic, and hybrid materials offer a biomimetic structure, enhance cell attachment, and release bioactive molecules that promote the axonal extension of severed nerves. Scaffold-based preclinical studies have shown promising results on enhancing nerve repair; however, they are limited by the immune response and fabrication, scalability, and cost. Nevertheless, advances in manufacturing, including 3D bioprinting, and other strategies, such as gene editing by CRISPR, will overcome these shortcomings. The opportunity for the development of individualized approaches and specific treatment plans for each patient will also increase the effectiveness of bioactive materials for the treatment of nerve injuries. Combining bioactive materials with the neural interface can develop new reliable therapeutic solutions, particularly for neuroprosthetics. Finally, it is essential to stress a multidisciplinary focus, and future studies are needed to enhance the potential of bioactive materials for patients with nerve injuries and the field of regenerative medicine. Full article

(This article belongs to the Special Issue Active Biomedical Materials and Their Applications, 2nd Edition)

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19 pages, 1935 KiB

Open AccessArticle

Mechanical Properties and Functional Assessment of PMMA Bone Cements Modified with Glassy Carbon

by Robert Karpiński and Jakub Szabelski

J. Funct. Biomater. 2025, 16(7), 254; https://doi.org/10.3390/jfb16070254 - 9 Jul 2025

Abstract

Poly(methyl methacrylate) (PMMA)-based bone cements are widely used in orthopaedic surgery, yet their inherent brittleness, lack of bioactivity, and exothermic polymerization remain critical limitations. Recent strategies have focused on modifying PMMA with functional additives to improve not only mechanical performance but also thermal [...] Read more.

Poly(methyl methacrylate) (PMMA)-based bone cements are widely used in orthopaedic surgery, yet their inherent brittleness, lack of bioactivity, and exothermic polymerization remain critical limitations. Recent strategies have focused on modifying PMMA with functional additives to improve not only mechanical performance but also thermal behaviour and biological interactions. This study investigates the mechanical properties of two commercial PMMA cements—Palamed^® (antibiotic-free) and Refobacin Plus G (gentamicin-loaded)—reinforced with glassy carbon (GC) particles of two different grain sizes (0.4–1.2 µm and 20–50 µm) and various concentrations. The results demonstrate that coarse GC particles (20–50 µm) significantly reduced compressive strength, particularly in the antibiotic-loaded cement. In contrast, the incorporation of fine GC particles (0.4–1.2 µm) did not markedly impair mechanical performance in Palamed^®, suggesting better compatibility with the PMMA matrix. In addition to mechanical enhancement, the structural and chemical stability of glassy carbon may contribute to improved biological response and reduced polymerization heat. These findings highlight the potential of glassy carbon as a functional additive for designing PMMA-based biomaterials that combine improved mechanical properties with favourable characteristics for long-term implant integration. Full article

(This article belongs to the Special Issue State of the Art: Biomaterials in Bone Implant and Regeneration)

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16 pages, 1856 KiB

Open AccessArticle

Biomimetic Hydrogels for In Vitro Modelling of Nucleus Pulposus Degeneration: Effects of Extracellular Matrix Compositional Change on Physicochemical Properties and Cell Phenotype

by Narjes Rashidi, Nicholas Dowell, Derek Covill, John Shepperd and Matteo Santin

J. Funct. Biomater. 2025, 16(7), 253; https://doi.org/10.3390/jfb16070253 - 8 Jul 2025

Abstract

The intervertebral disc, an anatomical compartment interposed between vertebral bodies, plays a key role in spine flexibility and compression loading. It comprises three tissues: the nucleus pulposus, the annulus fibrosus, and the end plates. Degeneration-related changes in the extracellular matrix of the nucleus [...] Read more.

The intervertebral disc, an anatomical compartment interposed between vertebral bodies, plays a key role in spine flexibility and compression loading. It comprises three tissues: the nucleus pulposus, the annulus fibrosus, and the end plates. Degeneration-related changes in the extracellular matrix of the nucleus pulposus upon ageing or pathological conditions prompted the present investigation into the impact of proteoglycan reduction, the main constituent of the healthy nucleus pulposus, on its physicochemical properties and cellular phenotypical changes. To mimic the native extracellular matrix, three-dimensional NP-mimicking constructs were developed using a biomimetic hydrogel composed of collagen type I, collagen type II, and proteoglycans. This system was fabricated using a bottom-up approach, employing highly pure monomeric collagen types I and II, which were induced to form a reconstituted fibrillar structure closely resembling the natural NP microenvironment. A comprehensive physicochemical characterization was conducted at varying proteoglycan percentages using scanning electron microscopy (SEM), FTIR, rheological tests, and water retention property analysis. The effect of microenvironment changes on the phenotype of nucleus pulposus cells was studied by their encapsulation within the various collagen–proteoglycan hydrogels. The morphological and immunochemistry analysis of the cells was performed to study the cell–matrix adhesion pathways and the expression of the cellular regulator hypoxia-inducible factor 1 alpha. These were linked to the analysis of the synthesis of healthy or pathological extracellular matrix components. The findings reveal that the reduction in proteoglycan content in the nucleus pulposus tissue triggers a pathological pathway, impairing the rheological and water retention properties. Consequently, the cell phenotypes are altered, inducing the synthesis of collagen type I rather than securing the natural physiological remodelling process by the synthesis of collagen type II and proteoglycans. Identifying the proteoglycan content threshold that triggers these pathological phenotypical changes could provide new diagnostic markers and early therapeutic strategies for intervertebral disc degeneration. Full article

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

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22 pages, 4137 KiB

Open AccessArticle

Biocompatibility of Hydraulic Calcium Silicate-Based Cement MTA Flow^TM on Human Dental Pulp Stem Cells In Vitro

by Paulius Tušas, Josette Camilleri, Milda Alksnė, Egidijus Šimoliūnas, Saulius Drukteinis, Eglė Marija Urbonė, Virginija Bukelskienė, Vygandas Rutkūnas and Vytautė Pečiulienė

J. Funct. Biomater. 2025, 16(7), 252; https://doi.org/10.3390/jfb16070252 - 7 Jul 2025

Abstract

Aim: hydraulic calcium silicate-based cements (HCSCs) are widely used in endodontics for vital pulp therapy and other clinical procedures due to their favorable physicochemical and biological properties. This study evaluates the biological properties of two HCSCs—MTA Flow™ and MTA Flow™ White (in a [...] Read more.

Aim: hydraulic calcium silicate-based cements (HCSCs) are widely used in endodontics for vital pulp therapy and other clinical procedures due to their favorable physicochemical and biological properties. This study evaluates the biological properties of two HCSCs—MTA Flow™ and MTA Flow™ White (in a 3:2 liquid-to-powder ratio, thick consistency)—on human dental pulp stem cells (hDPSCs). Methodology: hDPSCs were exposed to leachates from MTA Flow™, MTA Flow™ White, and ProRoot^® MTA. pH changes, cytotoxicity, cell proliferation, cell morphology, and cell death (apoptosis/necrosis) were assessed in vitro. Results: MTA Flow™ White and ProRoot^® MTA leachates produced a strongly alkaline pH (~10–12) compared to the negative control, whereas MTA Flow™ leachate caused a smaller pH increase (~9.4). Freshly mixed cements showed moderate cytotoxicity (around 40–60% cell viability at 100% concentration), while hardened cement leachates did not significantly affect cell viability. At 100% concentration, MTA Flow™ and MTA Flow™ White leachates significantly inhibited hDPSC proliferation and caused cell death, but at lower concentrations (≤50%) they supported cell viability and proliferation comparable to ProRoot^® MTA. hDPSCs exposed to MTA Flow™ and MTA Flow™ White leachates appeared more elongated morphologically than those exposed to ProRoot^® MTA. Notably, cells treated with MTA Flow™ White leachates were significantly smaller than those treated with MTA Flow™. Conclusions: MTA Flow™ and MTA Flow™ White, used in 3:2 thick consistency, demonstrated biocompatibility comparable to ProRoot^® MTA in vitro. While 100% leachates showed moderate cytotoxicity, lower concentration dilutions (≤50%) supported hDPSC viability, proliferation, and morphology. These findings support their potential as safe alternatives for vital pulp therapy. Further in vivo studies and dynamic models are needed to confirm long-term biological performance. Full article

(This article belongs to the Special Issue Role of Dental Biomaterials in Promoting Oral Health)

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14 pages, 2438 KiB

Open AccessArticle

Histologic and Histomorphometric Evaluation of Bone Regeneration Using Human Allogeneic Bone Graft with or Without Mesenchymal Stem Cell–Conditioned Media in a Rabbit Calvarial Defect Model

by Hyung-Gyun Kim, Yong-Suk Moon and Dong-Seok Sohn

J. Funct. Biomater. 2025, 16(7), 251; https://doi.org/10.3390/jfb16070251 - 7 Jul 2025

Abstract

Alveolar bone loss due to trauma, extraction, or periodontal disease often requires bone grafting prior to implant placement. Although human allograft bone is widely used as an alternative to autograft, it has limited osteoinductive potential and a prolonged healing time. Mesenchymal stem cell–conditioned [...] Read more.

Alveolar bone loss due to trauma, extraction, or periodontal disease often requires bone grafting prior to implant placement. Although human allograft bone is widely used as an alternative to autograft, it has limited osteoinductive potential and a prolonged healing time. Mesenchymal stem cell–conditioned media (MSC-CM), rich in paracrine factors, has emerged as a promising adjunct to enhance bone regeneration. This study evaluated the regenerative effect of MSC-CM combined with human allograft bone in a rabbit calvarial defect model. Bilateral 8 mm defects were created in eight rabbits. Each animal received a human allograft alone (HB group) on one side and an allograft mixed with MSC-CM (HB+GF group) on the other. Histological and histomorphometric analyses were performed at 2 and 8 weeks postoperatively. Both groups showed new bone formation, but the HB+GF group demonstrated significantly greater bone regeneration at both time points (p < 0.05). New bone extended into the defect center in the HB+GF group. Additionally, greater graft resorption and marrow formation were observed in this group at 8 weeks. These findings suggest that MSC-CM enhances the osteogenic performance of human allograft bone and may serve as a biologically active adjunct for bone regeneration. Full article

(This article belongs to the Special Issue 15th Anniversary of JFB—Functional Biomaterials for Bone Regeneration and Repair)

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14 pages, 3978 KiB

Open AccessArticle

A Novel Self-Expanding Transcatheter Mitral Valve with Dual Annulus/Valve Diameter

by Irina Yu. Zhuravleva

J. Funct. Biomater. 2025, 16(7), 250; https://doi.org/10.3390/jfb16070250 - 7 Jul 2025

Abstract

Background: The development of transcatheter mitral valves (TMVs) represents a major advancement in cardiology, driven in part by the growing elderly population. Elderly patients frequently suffer from secondary mitral regurgitation but are often ineligible for surgical valve replacement due to high procedural risks. [...] Read more.

Background: The development of transcatheter mitral valves (TMVs) represents a major advancement in cardiology, driven in part by the growing elderly population. Elderly patients frequently suffer from secondary mitral regurgitation but are often ineligible for surgical valve replacement due to high procedural risks. This study aimed to develop a self-expanding TMV stent fabricated from a single nitinol tube, featuring two distinct central zones: a smaller-diameter valve-containing segment and a larger-diameter anchoring segment for the mitral annulus. Methods: We used the COMSOL Multiphysics 6.0 software package for biotechnical engineering. Prototypes of stents and valves were manufactured in five sizes following a 22 Fr delivery system compatibility assessment and pulsatile-flow testing. Results: We bioengineered a novel stent design with an integrated porcine pericardial valve. The stents were laser-cut from nitinol tubes (4.5 mm outer diameter, 0.45 mm wall thickness) and heat-treated to achieve spatial configurations compatible with fibrous ring diameters of 40, 42, 44, 46, and 48 mm. Pericardial leaflets and coverings were then mounted onto the stents. The resulting valves were successfully loaded into a 24 Fr delivery system and exhibited proper opening and closing function under pulsatile-flow testing. Conclusions: Our findings confirm the feasibility of a single-component, dual-diameter TMV stent, offering a promising solution for high-risk patients with mitral regurgitation. Full article

(This article belongs to the Special Issue Medical Implants for Biomedical Applications)

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42 pages, 1721 KiB

Open AccessReview

Electrospinning Enables Opportunity for Green and Effective Antibacterial Coatings of Medical Devices

by Saverio Caporalini, Bahareh Azimi, Samir Zergat, Mahdi Ansari Chaharsoughi, Homa Maleki, Giovanna Batoni and Serena Danti

J. Funct. Biomater. 2025, 16(7), 249; https://doi.org/10.3390/jfb16070249 - 6 Jul 2025

Abstract

The growing antimicrobial resistance and the increasing environmental concerns associated with conventional antibacterial agents have prompted a search for more effective and sustainable alternatives. Biopolymer-based nanofibers are promising candidates to produce environment-friendly antibacterial coatings, owing to their high surface-to-volume ratio, structural adaptability, and [...] Read more.

The growing antimicrobial resistance and the increasing environmental concerns associated with conventional antibacterial agents have prompted a search for more effective and sustainable alternatives. Biopolymer-based nanofibers are promising candidates to produce environment-friendly antibacterial coatings, owing to their high surface-to-volume ratio, structural adaptability, and tunable porosity. These features make them particularly well-suited for delivering antimicrobial agents in a controlled manner and for physically modifying the surface of medical devices. This review critically explores recent advances in the use of electrospun fibers enhanced with natural antimicrobial agents as eco-friendly surface coatings. The mechanisms of antibacterial action, key factors affecting their efficacy, and comparisons with conventional antibacterial agents are discussed herein. Emphasis is placed on the role of a “green electrospinning” process, which utilizes bio-based materials and nontoxic solvents, to enable coatings able to better combat antibiotic-resistant pathogens. Applications in various clinical settings, including implants, wound dressings, surgical textiles, and urinary devices, are explored. Finally, the environmental benefits and prospects for the scalability and sustainability of green coatings are discussed to underscore their relevance to next-generation, sustainable solutions in healthcare. Full article

(This article belongs to the Special Issue Advanced Technologies for Processing Functional Biomaterials)

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20 pages, 20541 KiB

Open AccessArticle

Influence of Stent Structure on Mechanical and Degradation Properties of Poly (Lactic Acid) Vascular Stent

by Shicheng He, Qiang Chen and Zhiyong Li

J. Funct. Biomater. 2025, 16(7), 248; https://doi.org/10.3390/jfb16070248 - 6 Jul 2025

Abstract

Biodegradable vascular stents (BVSs) face challenges related to inadequate mechanical strength, which can lead to adverse clinical outcomes. Improving the mechanical behavior of biodegradable vascular stents through structural design has been extensively explored. However, the corresponding effects of these mechanical enhancements on degradation [...] Read more.

Biodegradable vascular stents (BVSs) face challenges related to inadequate mechanical strength, which can lead to adverse clinical outcomes. Improving the mechanical behavior of biodegradable vascular stents through structural design has been extensively explored. However, the corresponding effects of these mechanical enhancements on degradation characteristics remain under-investigated. The present work focuses on examining how different stent design strategies affect the mechanical behavior and degradation characteristics of poly (lactic acid) (PLA) stents. The commercial PLA stent DESolve was adopted, and nine modified stents were constructed based on the geometrical configuration of the DESolve stent. The mechanical properties of the modified stents during radial crimping and three-point bending simulations were thoroughly studied. The degradation dynamics of the stents were characterized by four indices (i.e., mean number average molecular weight, residual volume fraction, mean von Mises stress, and stent diameter). The results indicated that both the widening ratio and direction affected the mechanical performance of the stents by increasing the radial stiffness and radial strength, minimizing recoil%, and decreasing the bending flexibility. Although the widening direction had a relatively minor influence on stent degradation, the associated increase in material volume contributed to an improved volumetric integrity and enhanced lumen preservation. This study established a theoretical basis for evaluating both the mechanical and degradation behaviors of PLA stents, offering valuable insights for future structural design optimization. Full article

(This article belongs to the Special Issue Bio-Additive Manufacturing in Materials Science)

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12 pages, 3142 KiB

Open AccessArticle

The Influence of Drying Time, Application Mode, and Agitation on the Dentin Bond Strength of a Novel Mesoporous Bioactive Glass-Containing Universal Dentin Adhesive

by Jiyoung Kwon, Jungwon Kim, Dongseok Choi and Duck-Su Kim

J. Funct. Biomater. 2025, 16(7), 247; https://doi.org/10.3390/jfb16070247 - 5 Jul 2025

Abstract

This study evaluated the influence of drying time, application mode, and agitation on the micro-tensile bond strength (μTBS) of a novel mesoporous bioactive glass-containing universal adhesive (Hi-Bond Universal). Twelve experimental groups were established according to drying time (blot-dry, 10 s dry, or 20 [...] Read more.

This study evaluated the influence of drying time, application mode, and agitation on the micro-tensile bond strength (μTBS) of a novel mesoporous bioactive glass-containing universal adhesive (Hi-Bond Universal). Twelve experimental groups were established according to drying time (blot-dry, 10 s dry, or 20 s dry), application mode (total-etch or self-etch), and agitation (with or without). The μTBS test and failure mode analysis were performed for each experimental group (n = 20), and an adhesive interface was observed using field-emission scanning electron microscopy. The μTBS of all experimental groups was analyzed using a three-way ANOVA and Tukey’s honestly significant difference (HSD) post hoc test (α = 0.05). The total-etch mode yielded higher μTBS than the self-etch mode in the blot-dry and 10 s dry groups (p < 0.05). Agitation also significantly increased the μTBS in the blot-dry and 10 s dry groups for both application modes (p < 0.05). However, application mode and agitation had no effect on the μTBS in the 20 s dry group (p > 0.05). FE-SEM revealed longer and more uniform resin tags after agitation in the blot-dry and 10 s dry groups for both application modes. In conclusion, total-etch mode and agitation effectively increased the bond strength of mesoporous bioactive glass-containing universal adhesives. Full article

(This article belongs to the Special Issue Recent Advancements in Dental Restorative Materials)

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Journal of Functional Biomaterials

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