Journal of Functional Biomaterials

17 pages, 9342 KiB

Open AccessEditor’s ChoiceArticle

Angiogenic Potential of Co-Cultured Human Umbilical Vein Endothelial Cells and Adipose Stromal Cells in Customizable 3D Engineered Collagen Sheets

by Philipp Nessbach, Sascha Schwarz, Tanja D. Becke, Hauke Clausen-Schaumann, Hans-Guenther Machens and Stefanie Sudhop

J. Funct. Biomater. 2022, 13(3), 107; https://doi.org/10.3390/jfb13030107 - 29 Jul 2022

Cited by 2 | Viewed by 2904

Abstract

The wound healing process is much more complex than just the four phases of hemostasis, inflammation, proliferation, and maturation. Three-dimensional (3D) scaffolds made of biopolymers or ECM molecules using bioprinting can be used to promote the wound healing process, especially for complex 3D [...] Read more.

The wound healing process is much more complex than just the four phases of hemostasis, inflammation, proliferation, and maturation. Three-dimensional (3D) scaffolds made of biopolymers or ECM molecules using bioprinting can be used to promote the wound healing process, especially for complex 3D tissue lesions like chronic wounds. Here, a 3D-printed mold has been designed to produce customizable collagen type-I sheets containing human umbilical vein endothelial cells (HUVECs) and adipose stromal cells (ASCs) for the first time. In these 3D collagen sheets, the cellular activity leads to a restructuring of the collagen matrix. The upregulation of the growth factors Serpin E1 and TIMP-1 could be demonstrated in the 3D scaffolds with ACSs and HUVECs in co-culture. Both growth factors play a key role in the wound healing process. The capillary-like tube formation of HUVECs treated with supernatant from the collagen sheets revealed the secretion of angiogenic growth factors. Altogether, this demonstrates that collagen type I combined with the co-cultivation of HUVECs and ACSs has the potential to accelerate the process of angiogenesis and, thereby, might promote wound healing. Full article

(This article belongs to the Special Issue Smart Biomaterials for Soft and Hard Tissue Repair and Regeneration)

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15 pages, 2466 KiB

Open AccessEditor’s ChoiceArticle

Effect of Alumina Particles on the Osteogenic Ability of Osteoblasts

by Ashish Ranjan Sharma, Yeon-Hee Lee, Buyankhishig Gankhuyag, Chiranjib Chakraborty and Sang-Soo Lee

J. Funct. Biomater. 2022, 13(3), 105; https://doi.org/10.3390/jfb13030105 - 28 Jul 2022

Cited by 6 | Viewed by 2864

Abstract

Biomaterials are used as implants for bone and dental disabilities. However, wear particles from the implants cause osteolysis following total joint arthroplasty (TJA). Ceramic implants are considered safe and elicit a minimal response to cause periprosthetic osteolysis. However, few reports have highlighted the [...] Read more.

Biomaterials are used as implants for bone and dental disabilities. However, wear particles from the implants cause osteolysis following total joint arthroplasty (TJA). Ceramic implants are considered safe and elicit a minimal response to cause periprosthetic osteolysis. However, few reports have highlighted the adverse effect of ceramic particles such as alumina (Al₂O₃) on various cell types. Hence, we aimed to investigate the effect of Al₂O₃ particles on osteoprogenitors. A comparative treatment of Al₂O₃, Ti, and UHMWPE particles to osteoprogenitors at a similar concentration of 200 μg/mL showed that only Al₂O₃ particles were able to suppress the early and late differentiation markers of osteoprogenitors, including collagen synthesis, alkaline phosphatase (ALP) activity and mRNA expression of Runx2, OSX, Col1α, and OCN. Al₂O₃ particles even induced inflammation and activated the NFkB signaling pathway in osteoprogenitors. Moreover, bone-forming signals such as the WNT/β-catenin signaling pathway were inhibited by the Al₂O₃ particles. Al₂O₃ particles were found to induce the mRNA expression of WNT/β-catenin signaling antagonists such as DKK2, WIF, and sFRP1 several times in osteoprogenitors. Taken together, this study highlights a mechanistic view of the effect of Al₂O₃ particles on osteoprogenitors and suggests therapeutic targets such as NFĸB and WNT signaling pathways for ceramic particle-induced osteolysis. Full article

(This article belongs to the Special Issue Biocompatibility of Functional Biomaterials)

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17 pages, 16956 KiB

Open AccessEditor’s ChoiceArticle

Geometry-Based Computational Fluid Dynamic Model for Predicting the Biological Behavior of Bone Tissue Engineering Scaffolds

by Abdalla M. Omar, Mohamed H. Hassan, Evangelos Daskalakis, Gokhan Ates, Charlie J. Bright, Zhanyan Xu, Emily J. Powell, Wajira Mirihanage and Paulo J. D. S. Bartolo

J. Funct. Biomater. 2022, 13(3), 104; https://doi.org/10.3390/jfb13030104 - 27 Jul 2022

Cited by 23 | Viewed by 4237

Abstract

The use of biocompatible and biodegradable porous scaffolds produced via additive manufacturing is one of the most common approaches in tissue engineering. The geometric design of tissue engineering scaffolds (e.g., pore size, pore shape, and pore distribution) has a significant impact on their [...] Read more.

The use of biocompatible and biodegradable porous scaffolds produced via additive manufacturing is one of the most common approaches in tissue engineering. The geometric design of tissue engineering scaffolds (e.g., pore size, pore shape, and pore distribution) has a significant impact on their biological behavior. Fluid flow dynamics are important for understanding blood flow through a porous structure, as they determine the transport of nutrients and oxygen to cells and the flushing of toxic waste. The aim of this study is to investigate the impact of the scaffold architecture, pore size and distribution on its biological performance using Computational Fluid Dynamics (CFD). Different blood flow velocities (BFV) induce wall shear stresses (WSS) on cells. WSS values above 30 mPa are detrimental to their growth. In this study, two scaffold designs were considered: rectangular scaffolds with uniform square pores (300, 350, and 450 µm), and anatomically designed circular scaffolds with a bone-like structure and pore size gradient (476–979 µm). The anatomically designed scaffolds provided the best fluid flow conditions, suggesting a 24.21% improvement in the biological performance compared to the rectangular scaffolds. The numerical observations are aligned with those of previously reported biological studies. Full article

(This article belongs to the Special Issue Experimentation, Numerical and Analytical Methods in Functional Biomaterials)

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18 pages, 4654 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

When Nothing Turns Itself Inside out and Becomes Something: Coating Poly(Lactic-Co-Glycolic Acid) Spheres with Hydroxyapatite Nanoparticles vs. the Other Way Around

by Vuk Uskoković and Victoria M. Wu

J. Funct. Biomater. 2022, 13(3), 102; https://doi.org/10.3390/jfb13030102 - 23 Jul 2022

Cited by 5 | Viewed by 2894

Abstract

To stabilize drugs physisorbed on the surface of hydroxyapatite (HAp) nanoparticles and prevent burst release, these nanoparticles are commonly coated with polymers. Bioactive HAp, however, becomes shielded from the surface of such core/shell entities, which partially defeats the purpose of using it. The [...] Read more.

To stabilize drugs physisorbed on the surface of hydroxyapatite (HAp) nanoparticles and prevent burst release, these nanoparticles are commonly coated with polymers. Bioactive HAp, however, becomes shielded from the surface of such core/shell entities, which partially defeats the purpose of using it. The goal of this study was to assess the biological and pharmacokinetic effects of inverting this classical core/shell structure by coating poly(lactic-co-glycolic acid) (PLGA) spheres with HAp nanoparticles. The HAp shell did not hinder the release of vancomycin; rather, it increased the release rate to a minor degree, compared to that from undecorated PLGA spheres. The decoration of PLGA spheres with HAp induced lesser mineral deposition and lesser upregulation of osteogenic markers compared to those induced by the composite particles where HAp nanoparticles were embedded inside the PLGA spheres. This was explained by homeostatic mechanisms governing the cell metabolism, which ensure than the sensation of a product of this metabolism in the cell interior or exterior is met with the reduction in the metabolic activity. The antagonistic relationship between proliferation and bone production was demonstrated by the higher proliferation rate of cells challenged with HAp-coated PLGA spheres than of those treated with PLGA-coated HAp. It is concluded that the overwhelmingly positive response of tissues to HAp-coated biomaterials for bone replacement is unlikely to be due to the direct induction of new bone growth in osteoblasts adhering to the HAp coating. Rather, these positive effects are consequential to more elementary aspects of cell attachment, mechanotransduction, and growth at the site of contact between the HAp-coated material and the tissue. Full article

(This article belongs to the Special Issue Functionalized Biomimetic Calcium Phosphates 2.0)

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14 pages, 2722 KiB

Open AccessEditor’s ChoiceReview

A Review of Woven Tracheal Stents: Materials, Structures, and Application

by Chen Xu, Yanxue Ma, Haihua Huang, Zheng Ruan and Yuling Li

J. Funct. Biomater. 2022, 13(3), 96; https://doi.org/10.3390/jfb13030096 - 16 Jul 2022

Cited by 5 | Viewed by 3595

Abstract

The repair and reconstruction of tracheal defects is a challenging clinical problem. Due to the wide choice of materials and structures, weaving technology has shown unique advantages in simulating the multilayer structure of the trachea and providing reliable performance. Currently, most woven stent-based [...] Read more.

The repair and reconstruction of tracheal defects is a challenging clinical problem. Due to the wide choice of materials and structures, weaving technology has shown unique advantages in simulating the multilayer structure of the trachea and providing reliable performance. Currently, most woven stent-based stents focus only on the effect of materials on stent performance while ignoring the direct effect of woven process parameters on stent performance, and the advantages of weaving technology in tissue regeneration have not been fully exploited. Therefore, this review will introduce the effects of stent materials and fabric construction on the performance of tracheal stents, focusing on the effects of weaving process parameters on stent performance. We will summarize the problems faced by woven stents and possible directions of development in the hope of broadening the technical field of artificial trachea preparation. Full article

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

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15 pages, 13375 KiB

Open AccessEditor’s ChoiceArticle

Influence of Electric Field on Proliferation Activity of Human Dermal Fibroblasts

by Almaz Kamalov, Mikhail Shishov, Natalia Smirnova, Vera Kodolova-Chukhontseva, Irina Dobrovol’skaya, Konstantin Kolbe, Andrei Didenko, Elena Ivan’kova, Vladimir Yudin and Pierfrancesco Morganti

J. Funct. Biomater. 2022, 13(3), 89; https://doi.org/10.3390/jfb13030089 - 29 Jun 2022

Cited by 5 | Viewed by 3855

Abstract

In this work, an electrically conductive composite based on thermoplastic polyimide and graphene was obtained and used as a bioelectrode for electrical stimulation of human dermal fibroblasts. The values of the electrical conductivity of the obtained composite films varied from 10⁻¹⁵ to [...] Read more.

In this work, an electrically conductive composite based on thermoplastic polyimide and graphene was obtained and used as a bioelectrode for electrical stimulation of human dermal fibroblasts. The values of the electrical conductivity of the obtained composite films varied from 10⁻¹⁵ to 10² S/m with increasing graphene content (from 0 to 5.0 wt.%). The characteristics of ionic and electronic currents flowing through the matrix with the superposition of cyclic potentials ± 100 mV were studied. The high stability of the composite was established during prolonged cycling (130 h) in an electric field with a frequency of 0.016 Hz. It was established that the composite films based on polyimide and graphene have good biocompatibility and are not toxic to fibroblast cells. It was shown that preliminary electrical stimulation increases the proliferative activity of human dermal fibroblasts in comparison with intact cells. It is revealed that an electric field with a strength E = 0.02–0.04 V/m applied to the polyimide films containing 0.5–3.0 wt.% of the graphene nanoparticles activates cellular processes (adhesion, proliferation). Full article

(This article belongs to the Special Issue Bionanotechnology in Skin Nutritional Cosmetics for a Beauty from Within)

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14 pages, 5070 KiB

Open AccessEditor’s ChoiceArticle

Hydroxyapatite Decorated with Tungsten Oxide Nanoparticles: New Composite Materials against Bacterial Growth

by Francesca Silingardi, Francesca Bonvicini, Maria Cristina Cassani, Raffaello Mazzaro, Katia Rubini, Giovanna Angela Gentilomi, Adriana Bigi and Elisa Boanini

J. Funct. Biomater. 2022, 13(3), 88; https://doi.org/10.3390/jfb13030088 - 24 Jun 2022

Cited by 9 | Viewed by 2677

Abstract

The availability of biomaterials able to counteract bacterial colonization is one of the main requirements of functional implants and medical devices. Herein, we functionalized hydroxyapatite (HA) with tungsten oxide (WO₃) nanoparticles in the aim to obtain composite materials with improved biological [...] Read more.

The availability of biomaterials able to counteract bacterial colonization is one of the main requirements of functional implants and medical devices. Herein, we functionalized hydroxyapatite (HA) with tungsten oxide (WO₃) nanoparticles in the aim to obtain composite materials with improved biological performance. To this purpose, we used HA, as well as HA functionalized with polyacrilic acid (HAPAA) or poly(ethylenimine) (HAPEI), as supports and polyvinylpyrrolidone (PVP) as stabilizing agent for WO₃ nanoparticles. The number of nanoparticles loaded on the substrates was determined through Molecular Plasma-Atomic Emission Spectroscopy and is quite small, so it cannot be detected through X-ray diffraction analysis. It increases from HAPAA, to HA, to HAPEI, in agreement with the different values of zeta potential of the different substrates. HRTEM and STEM images show the dimensions of the nanoparticles are very small, less than 1 nm. In physiological solution HA support displays a greater tungsten cumulative release than HAPEI, despite its smaller loaded amount. Indeed, WO₃ nanoparticles-functionalized HA exhibits a remarkable antibacterial activity against the Gram-positive Staphylococcus aureus in absence of cytotoxicity, which could be usefully exploited in the biomedical field. Full article

(This article belongs to the Special Issue Functionalized Biomimetic Calcium Phosphates 2.0)

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35 pages, 3655 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Antibacterial Designs for Implantable Medical Devices: Evolutions and Challenges

by Huiliang Cao, Shichong Qiao, Hui Qin and Klaus D. Jandt

J. Funct. Biomater. 2022, 13(3), 86; https://doi.org/10.3390/jfb13030086 - 21 Jun 2022

Cited by 29 | Viewed by 5047

Abstract

The uses of implantable medical devices are safer and more common since sterilization methods and techniques were established a century ago; however, device-associated infections (DAIs) are still frequent and becoming a leading complication as the number of medical device implantations keeps increasing. This [...] Read more.

The uses of implantable medical devices are safer and more common since sterilization methods and techniques were established a century ago; however, device-associated infections (DAIs) are still frequent and becoming a leading complication as the number of medical device implantations keeps increasing. This urges the world to develop instructive prevention and treatment strategies for DAIs, boosting the studies on the design of antibacterial surfaces. Every year, studies associated with DAIs yield thousands of publications, which here are categorized into four groups, i.e., antibacterial surfaces with long-term efficacy, cell-selective capability, tailored responsiveness, and immune-instructive actions. These innovations are promising in advancing the solution to DAIs; whereas most of these are normally quite preliminary “proof of concept” studies lacking exact clinical scopes. To help identify the flaws of our current antibacterial designs, clinical features of DAIs are highlighted. These include unpredictable onset, site-specific incidence, and possibly involving multiple and resistant pathogenic strains. The key point we delivered is antibacterial designs should meet the specific requirements of the primary functions defined by the “intended use” of an implantable medical device. This review intends to help comprehend the complex relationship between the device, pathogens, and the host, and figure out future directions for improving the quality of antibacterial designs and promoting clinical translations. Full article

(This article belongs to the Special Issue State-of-the-Art Functional Biomaterials in China)

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14 pages, 7533 KiB

Open AccessEditor’s ChoiceArticle

Direct Ink Write Printing of Chitin-Based Gel Fibers with Customizable Fibril Alignment, Porosity, and Mechanical Properties for Biomedical Applications

by Devis Montroni, Takeru Kobayashi, Taige Hao, Derek Lublin, Tomoko Yoshino and David Kisailus

J. Funct. Biomater. 2022, 13(2), 83; https://doi.org/10.3390/jfb13020083 - 16 Jun 2022

Cited by 7 | Viewed by 3391

Abstract

A fine control over different dimensional scales is a challenging target for material science since it could grant control over many properties of the final material. In this study, we developed a multivariable additive manufacturing process, direct ink write printing, to control different [...] Read more.

A fine control over different dimensional scales is a challenging target for material science since it could grant control over many properties of the final material. In this study, we developed a multivariable additive manufacturing process, direct ink write printing, to control different architectural features from the nano- to the millimeter scale during extrusion. Chitin-based gel fibers with a water content of around 1500% were obtained extruding a polymeric solution of chitin into a counter solvent, water, inducing instant solidification of the material. A certain degree of fibrillar alignment was achieved basing on the shear stress induced by the nozzle. In this study we took into account a single variable, the nozzle’s internal diameter (NID). In fact, a positive correlation between NID, fibril alignment, and mechanical resistance was observed. A negative correlation with NID was observed with porosity, exposed surface, and lightly with water content. No correlation was observed with maximum elongation (~50%), and the scaffold’s excellent biocompatibility, which appeared unaltered. Overall, a single variable allowed a customization of different material features, which could be further tuned, adding control over other aspects of the synthetic process. Moreover, this manufacturing could be potentially applied to any polymer. Full article

(This article belongs to the Special Issue Nanoengineered Materials for Biomedical Applications)

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13 pages, 2041 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Effect of a Self-Assembly Peptide on Surface Roughness and Hardness of Bleached Enamel

by Gabriela de A. P. Magalhães, May Anny A Fraga, Isaac J. de Souza Araújo, Rafael R. Pacheco, Américo B. Correr and Regina M. Puppin-Rontani

J. Funct. Biomater. 2022, 13(2), 79; https://doi.org/10.3390/jfb13020079 - 13 Jun 2022

Cited by 7 | Viewed by 3401

Abstract

After bleaching, enamel surfaces are damaged, contributing to erosion and tooth sensitivity. Although fluoride is used after bleaching to try and revert alterations, it is not capable of repairing tooth structure. This study compared the effect of a self-assembly peptide (P₁₁-4), [...] Read more.

After bleaching, enamel surfaces are damaged, contributing to erosion and tooth sensitivity. Although fluoride is used after bleaching to try and revert alterations, it is not capable of repairing tooth structure. This study compared the effect of a self-assembly peptide (P₁₁-4), with and without fluoride, and sodium fluoride (NaF 2%) on the Knoop microhardness (KHN) and surface roughness (Ra (μm)) of bleached enamel with an in-office bleaching regimen. Enamel blocks of bovine teeth (5 × 5 × 2 mm) with standardized surface hardness were bleached with 35% carbamide peroxide, following the manufacturer’s instructions. The teeth were randomly divided into the following groups (n = 7) according to post-bleaching treatment: no treatment (negative control) (C-); 2% NaF (NaF); Curodont™ Repair (Repair); and Curodont™ Protect (Protect). Specimens were stored in artificial saliva at 37 °C. To evaluate the effect of the post-bleaching treatments, KHN and Ra were measured before bleaching (baseline) and 24 h and 7 days after bleaching. Data were submitted to repeated measures ANOVA and Bonferroni tests (α = 0.05). There were significant interactions between the study factors (p = 0.001). After 7 days, Repair (572.50 ± 79.04) and Protect (583.00 ± 74.76) specimens showed increased surface KHN, with values higher than the NaF (465.50 ± 41.50) and C- (475.22 ± 58.95) baseline values. There was no significant difference in KHN at 24 h among groups (p = 0.587). At 24 h after bleaching, Repair was significantly different from all groups (p < 0.05). Repair showed the lowest Ra (μm) values (0.133 ± 0.035). After seven days, there was no significant difference in Ra values among groups when compared to the baseline. The use of P₁₁-4-based materials after bleaching resulted in the fastest recovery to baseline enamel properties. Full article

(This article belongs to the Special Issue Feature Papers in Dental Biomaterials)

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28 pages, 2047 KiB

Open AccessEditor’s ChoiceReview

Graphene Oxide (GO) Materials—Applications and Toxicity on Living Organisms and Environment

by Aminah N. Ghulam, Otávio A. L. dos Santos, Layla Hazeem, Bianca Pizzorno Backx, Mohamed Bououdina and Stefano Bellucci

J. Funct. Biomater. 2022, 13(2), 77; https://doi.org/10.3390/jfb13020077 - 10 Jun 2022

Cited by 125 | Viewed by 12469

Abstract

Graphene-based materials have attracted much attention due to their fascinating properties such as hydrophilicity, high dispersion in aqueous media, robust size, high biocompatibility, and surface functionalization ability due to the presence of functional groups and interactions with biomolecules such as proteins and nucleic [...] Read more.

Graphene-based materials have attracted much attention due to their fascinating properties such as hydrophilicity, high dispersion in aqueous media, robust size, high biocompatibility, and surface functionalization ability due to the presence of functional groups and interactions with biomolecules such as proteins and nucleic acid. Modified methods were developed for safe, direct, inexpensive, and eco-friendly synthesis. However, toxicity to the environment and animal health has been reported, raising concerns about their utilization. This review focuses primarily on the synthesis methods of graphene-based materials already developed and the unique properties that make them so interesting for different applications. Different applications are presented and discussed with particular emphasis on biological fields. Furthermore, antimicrobial potential and the factors that affect this activity are reviewed. Finally, questions related to toxicity to the environment and living organisms are revised by highlighting factors that may interfere with it. Full article

(This article belongs to the Special Issue Advanced Bioceramics)

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24 pages, 4731 KiB

Open AccessEditor’s ChoiceArticle

3D Plotting of Calcium Phosphate Cement and Melt Electrowriting of Polycaprolactone Microfibers in One Scaffold: A Hybrid Additive Manufacturing Process

by David Kilian, Max von Witzleben, Matthew Lanaro, Cynthia S. Wong, Corina Vater, Anja Lode, Mark C. Allenby, Maria A. Woodruff and Michael Gelinsky

J. Funct. Biomater. 2022, 13(2), 75; https://doi.org/10.3390/jfb13020075 - 8 Jun 2022

Cited by 15 | Viewed by 4324

Abstract

The fabrication of patient-specific scaffolds for bone substitutes is possible through extrusion-based 3D printing of calcium phosphate cements (CPC) which allows the generation of structures with a high degree of customization and interconnected porosity. Given the brittleness of this clinically approved material, the [...] Read more.

The fabrication of patient-specific scaffolds for bone substitutes is possible through extrusion-based 3D printing of calcium phosphate cements (CPC) which allows the generation of structures with a high degree of customization and interconnected porosity. Given the brittleness of this clinically approved material, the stability of open-porous scaffolds cannot always be secured. Herein, a multi-technological approach allowed the simultaneous combination of CPC printing with melt electrowriting (MEW) of polycaprolactone (PCL) microfibers in an alternating, tunable design in one automated fabrication process. The hybrid CPC+PCL scaffolds with varying CPC strand distance (800–2000 µm) and integrated PCL fibers featured a strong CPC to PCL interface. While no adverse effect on mechanical stiffness was detected by the PCL-supported scaffold design; the microfiber integration led to an improved integrity. The pore distance between CPC strands was gradually increased to identify at which critical CPC porosity the microfibers would have a significant impact on pore bridging behavior and growth of seeded cells. At a CPC strand distance of 1600 µm, after 2 weeks of cultivation, the incorporation of PCL fibers led to pore coverage by a human mesenchymal stem cell line and an elevated proliferation level of murine pre-osteoblasts. The integrated fabrication approach allows versatile design adjustments on different levels. Full article

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

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15 pages, 2990 KiB

Open AccessEditor’s ChoiceArticle

Rational Design and Characterisation of Novel Mono- and Bimetallic Antibacterial Linde Type A Zeolite Materials

by Emmanuel Oheix, Chloé Reicher, Habiba Nouali, Laure Michelin, Ludovic Josien, T. Jean Daou and Laurent Pieuchot

J. Funct. Biomater. 2022, 13(2), 73; https://doi.org/10.3390/jfb13020073 - 2 Jun 2022

Cited by 7 | Viewed by 3444

Abstract

The development of antimicrobial devices and surfaces requires the setup of suitable materials, able to store and release active principles. In this context, zeolites, which are microporous aluminosilicate minerals, hold great promise, since they are able to serve as a reservoir for metal-ions [...] Read more.

The development of antimicrobial devices and surfaces requires the setup of suitable materials, able to store and release active principles. In this context, zeolites, which are microporous aluminosilicate minerals, hold great promise, since they are able to serve as a reservoir for metal-ions with antimicrobial properties. Here, we report on the preparation of Linde Type A zeolites, partially exchanged with combinations of metal-ions (Ag⁺, Cu²⁺, Zn²⁺) at different loadings (0.1–11.9 wt.%). We combine X-ray fluorescence, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction to monitor the metal-ion contents, distribution, and conservation of the zeolite structure after exchange. Then, we evaluate their antimicrobial activity, using agar dilution and optical-density monitoring of Escherichia coli cultures. The results indicate that silver-loaded materials are at least 70-fold more active than the copper-, zinc-, and non-exchanged ones. Moreover, zeolites loaded with lower Ag⁺ concentrations remain active down to 0.1 wt.%, and their activities are directly proportional to the total Ag content. Sequential exchanges with two metal ions (Ag⁺ and either Cu²⁺, Zn²⁺) display synergetic or antagonist effects, depending on the quantity of the second metal. Altogether, this work shows that, by combining analytical and quantitative methods, it is possible to fine-tune the composition of bi-metal-exchanged zeolites, in order to maximise their antimicrobial potential, opening new ways for the development of next-generation composite zeolite-containing antimicrobial materials, with potential applications for the design of dental or bone implants, as well as biomedical devices and pharmaceutical products. Full article

(This article belongs to the Special Issue Antibacterial Biomaterials)

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31 pages, 8743 KiB

Open AccessEditor’s ChoiceReview

Biodegradable Iron and Porous Iron: Mechanical Properties, Degradation Behaviour, Manufacturing Routes and Biomedical Applications

by Mariana Salama, Maria Fátima Vaz, Rogério Colaço, Catarina Santos and Maria Carmezim

J. Funct. Biomater. 2022, 13(2), 72; https://doi.org/10.3390/jfb13020072 - 1 Jun 2022

Cited by 46 | Viewed by 6763

Abstract

Biodegradable metals have been extensively studied due to their potential use as temporary biomedical devices, on non-load bearing applications. These types of implants are requested to function for the healing period, and should degrade after the tissue heals. A balance between mechanical properties [...] Read more.

Biodegradable metals have been extensively studied due to their potential use as temporary biomedical devices, on non-load bearing applications. These types of implants are requested to function for the healing period, and should degrade after the tissue heals. A balance between mechanical properties requested at the initial stage of implantation and the degradation rate is required. The use of temporary biodegradable implants avoids a second surgery for the removal of the device, which brings high benefits to the patients and avoids high societal costs. Among the biodegradable metals, iron as a biodegradable metal has increased attention over the last few years, especially with the incorporation of additive manufacturing processes to obtain tailored geometries of porous structures, which give rise to higher corrosion rates. Withal by mimic natural bone hierarchical porosity, the mechanical properties of obtained structures tend to equalize that of human bone. This review article presents some of the most important works in the field of iron and porous iron. Fabrication techniques for porous iron are tackled, including conventional and new methods highlighting the unparalleled opportunities given by additive manufacturing. A comparison among the several methods is taken. The effects of the design and the alloying elements on the mechanical properties are also revised. Iron alloys with antibacterial properties are analyzed, as well as the biodegradation behavior and biocompatibility of iron. Although is necessary for further in vivo research, iron is presenting satisfactory results for upcoming biomedical applications, as orthopaedic temporary scaffolds and coronary stents. Full article

(This article belongs to the Special Issue Smart Biomaterials for Soft and Hard Tissue Repair and Regeneration)

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18 pages, 6492 KiB

Open AccessEditor’s ChoiceArticle

Antibacterial and Osteogenic Properties of Ag Nanoparticles and Ag/TiO₂ Nanostructures Prepared by Atomic Layer Deposition

by Denis Nazarov, Ilya Ezhov, Natalia Yudintceva, Maxim Shevtsov, Aida Rudakova, Vladimir Kalganov, Vladimir Tolmachev, Yuliya Zharova, Oleksiy Lutakov, Ludmila Kraeva, Elizaveta Rogacheva and Maxim Maximov

J. Funct. Biomater. 2022, 13(2), 62; https://doi.org/10.3390/jfb13020062 - 18 May 2022

Cited by 26 | Viewed by 3715

Abstract

The combination of titania nanofilms and silver nanoparticles (NPs) is a very promising material, with antibacterial and osseointegration-induced properties for titanium implant coatings. In this work, we successfully prepared TiO₂ nanolayer/Ag NP structures on titanium disks using atomic layer deposition (ALD). The [...] Read more.

The combination of titania nanofilms and silver nanoparticles (NPs) is a very promising material, with antibacterial and osseointegration-induced properties for titanium implant coatings. In this work, we successfully prepared TiO₂ nanolayer/Ag NP structures on titanium disks using atomic layer deposition (ALD). The samples were studied by scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS), contact angle measurements, and SEM-EDS. Antibacterial activity was tested against Staphylococcus aureus. The in vitro cytological response of MG-63 osteosarcoma and human fetal mesenchymal stem cells (FetMSCs) was examined using SEM study of their morphology, MTT test of viability and differentiation using alkaline phosphatase and osteopontin with and without medium-induced differentiation in the osteogenic direction. The samples with TiO₂ nanolayers, Ag NPs, and a TiO₂/Ag combination showed high antibacterial activity, differentiation in the osteogenic direction, and non-cytotoxicity. The medium for differentiation significantly improved osteogenic differentiation, but the ALD coatings also stimulated differentiation in the absence of the medium. The TiO₂/Ag samples showed the best antibacterial ability and differentiation in the osteogenic direction, indicating the success of the combining of TiO₂ and Ag to produce a multifunctional biocompatible and bactericidal material. Full article

(This article belongs to the Special Issue Biomaterials in Tissue, Biomedical and Surface Engineering)

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11 pages, 2342 KiB

Open AccessEditor’s ChoiceArticle

Physical and Chemical Characterization of Biomineralized Collagen with Different Microstructures

by Tianming Du, Yumiao Niu, Youjun Liu, Haisheng Yang, Aike Qiao and Xufeng Niu

J. Funct. Biomater. 2022, 13(2), 57; https://doi.org/10.3390/jfb13020057 - 13 May 2022

Cited by 8 | Viewed by 3469

Abstract

Mineralized collagen is the basic unit in hierarchically organized natural bone with different structures. Polyacrylic acid (PAA) and periodic fluid shear stress (FSS) are the most common chemical and physical means to induce intrafibrillar mineralization. In the present study, non-mineralized collagen, extrafibrillar mineralized [...] Read more.

Mineralized collagen is the basic unit in hierarchically organized natural bone with different structures. Polyacrylic acid (PAA) and periodic fluid shear stress (FSS) are the most common chemical and physical means to induce intrafibrillar mineralization. In the present study, non-mineralized collagen, extrafibrillar mineralized (EM) collagen, intrafibrillar mineralized (IM) collagen, and hierarchical intrafibrillar mineralized (HIM) collagen induced by PAA and FSS were prepared, respectively. The physical and chemical properties of these mineralized collagens with different microstructures were systematically investigated afterwards. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that mineralized collagen with different microstructures was prepared successfully. The pore density of the mineralized collagen scaffold is higher under the action of periodic FSS. Fourier transform infrared spectroscopy (FTIR) analysis showed the formation of the hydroxyapatite (HA) crystal. A significant improvement in the pore density, hydrophilicity, enzymatic stability, and thermal stability of the mineralized collagen indicated that the IM collagen under the action of periodic FSS was beneficial for maintaining collagen activity. HIM collagen fibers, which are prepared under the co-action of periodic FSS and sodium tripolyphosphate (TPP), may pave the way for new bone substitute material applications. Full article

(This article belongs to the Special Issue Biomechanical Study and Analysis for Cardiovascular/Skeletal Materials and Devices)

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13 pages, 5322 KiB

Open AccessEditor’s ChoiceArticle

Electrospun PHB/Chitosan Composite Fibrous Membrane and Its Degradation Behaviours in Different pH Conditions

by Yansheng Zhou, Ying Li, Daqing Li, Yidan Yin and Fenglei Zhou

J. Funct. Biomater. 2022, 13(2), 58; https://doi.org/10.3390/jfb13020058 - 13 May 2022

Cited by 14 | Viewed by 4158

Abstract

Peripheral nerve injury (PNI) is a neurological disorder that causes more than 9 million patients to suffer from dysfunction of moving and sensing. Using biodegradable polymers to fabricate an artificial nerve conduit that replicates the environment of the extracellular matrix and guides neuron [...] Read more.

Peripheral nerve injury (PNI) is a neurological disorder that causes more than 9 million patients to suffer from dysfunction of moving and sensing. Using biodegradable polymers to fabricate an artificial nerve conduit that replicates the environment of the extracellular matrix and guides neuron regeneration through the damaged sites has been researched for decades and has led to promising but primarily pre-clinical outcomes. However, few peripheral nerve conduits (PNCs) have been constructed from controllable biodegradable polymeric materials that can maintain their structural integrity or completely degrade during and after nerve regeneration respectively. In this work, a novel PNC candidate material was developed via the electrospinning of polyhydroxy butyrate/chitosan (PHB/CS) composite polymers. An SEM characterisation revealed the resultant PHB/CS nanofibres with 0, 1 and 2 wt/v% CS had less and smaller beads than the nanofibres at 3 wt/v% CS. The water contact angle (WCA) measurement demonstrated that the wettability of PHB/CS electrospun fibres was significantly improved by additional CS. Furthermore, both the thermogravimetric analysis (TGA) and differentiation scanning calorimetry (DSC) results showed that PHB/CS polymers can be blended in a single phase with a trifluoracetic solvent in all compositions. Besides, the reduction in the degradation temperature (from 286.9 to 229.9 °C) and crystallinity (from 81.0% to 52.1%) with increasing contents of CS were further proven. Moreover, we found that the degradability of the PHB/CS nanofibres subjected to different pH values rated in the order of acidic > alkaline > phosphate buffer solution (PBS). Based on these findings, it can be concluded that PHB/CS electrospun fibres with variable blending ratios may be used for designing PNCs with controlled biodegradability. Full article

(This article belongs to the Topic Advanced Functional Materials for Regenerative Medicine)

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15 pages, 3890 KiB

Open AccessEditor’s ChoiceArticle

Nanocomposite Hydrogel Produced from PEGDA and Laponite for Bone Regeneration

by Leila S. S. M. Magalhães, Danielle B. Andrade, Roosevelt D. S. Bezerra, Alan I. S. Morais, Francilio C. Oliveira, Márcia S. Rizzo, Edson C. Silva-Filho and Anderson O. Lobo

J. Funct. Biomater. 2022, 13(2), 53; https://doi.org/10.3390/jfb13020053 - 4 May 2022

Cited by 25 | Viewed by 5238

Abstract

Herein, a nanocomposite hydrogel was produced using laponite and polyethylene-glycol diacrylate (PEGDA), with or without Irgacure (IG), for application in bone tissue regeneration. The nanocomposites were characterized by X-ray diffraction (XRD), Fourier-Transform infrared spectroscopy (FTIR), and thermal analysis (TG/DTG). The XRD results showed [...] Read more.

Herein, a nanocomposite hydrogel was produced using laponite and polyethylene-glycol diacrylate (PEGDA), with or without Irgacure (IG), for application in bone tissue regeneration. The nanocomposites were characterized by X-ray diffraction (XRD), Fourier-Transform infrared spectroscopy (FTIR), and thermal analysis (TG/DTG). The XRD results showed that the crystallographic structure of laponite was preserved in the nanocomposite hydrogels after the incorporation of PEGDA and IG. The FTIR results indicated that PEGDA polymer chains were entangled on laponite in hydrogels. The TG/DTG found that the presence of laponite (Lap) improved the thermal stability of nanocomposite hydrogel. The toxicity tests by Artemia salina indicated that the nanocomposite hydrogels were not toxic, because the amount of live nauplii was 80.0%. In addition, in vivo tests demonstrated that the hydrogels had the ability to regenerate bone in a bone defect model of the tibiae of osteopenic rats. For the nanocomposite hydrogel (PEGDA + Lap nanocomposites + UV light), the formation of intramembranous bone in the soft callus was more intense in 66.7% of the animals. Thus, the results presented in this study evidence that nanocomposite hydrogels obtained from laponite and PEGDA have the potential for use in bone regeneration. Full article

(This article belongs to the Topic Materials in Implant Applications and Regenerative Medicine)

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16 pages, 12456 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Catalyst-Free Click Chemistry for Engineering Chondroitin Sulfate-Multiarmed PEG Hydrogels for Skin Tissue Engineering

by Gustavo F. Sousa, Samson Afewerki, Dalton Dittz, Francisco E. P. Santos, Daniele O. Gontijo, Sérgio R. A. Scalzo, Ana L. C. Santos, Lays C. Guimaraes, Ester M. Pereira, Luciola S. Barcelos, Semiramis J. H. Do Monte, Pedro P. G. Guimaraes, Fernanda R. Marciano and Anderson O. Lobo

J. Funct. Biomater. 2022, 13(2), 45; https://doi.org/10.3390/jfb13020045 - 18 Apr 2022

Cited by 8 | Viewed by 4329

Abstract

The quest for an ideal biomaterial perfectly matching the microenvironment of the surrounding tissues and cells is an endless challenge within biomedical research, in addition to integrating this with a facile and sustainable technology for its preparation. Engineering hydrogels through click chemistry would [...] Read more.

The quest for an ideal biomaterial perfectly matching the microenvironment of the surrounding tissues and cells is an endless challenge within biomedical research, in addition to integrating this with a facile and sustainable technology for its preparation. Engineering hydrogels through click chemistry would promote the sustainable invention of tailor-made hydrogels. Herein, we disclose a versatile and facile catalyst-free click chemistry for the generation of an innovative hydrogel by combining chondroitin sulfate (CS) and polyethylene glycol (PEG). Various multi-armed PEG-Norbornene (A-PEG-N) with different molecular sizes were investigated to generate crosslinked copolymers with tunable rheological and mechanical properties. The crosslinked and mechanically stable porous hydrogels could be generated by simply mixing the two clickable Tetrazine-CS (TCS) and A-PEG-N components, generating a self-standing hydrogel within minutes. The leading candidate (TCS-8A-PEG-N (40 kD)), based on the mechanical and biocompatibility results, was further employed as a scaffold to improve wound closure and blood flow in vivo. The hydrogel demonstrated not only enhanced blood perfusion and an increased number of blood vessels, but also desirable fibrous matrix orientation and normal collagen deposition. Taken together, these results demonstrate the potential of the hydrogel to improve wound repair and hold promise for in situ skin tissue engineering applications. Full article

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

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20 pages, 1328 KiB

Open AccessEditor’s ChoiceArticle

The Implant Proteome—The Right Surgical Glue to Fix Titanium Implants In Situ

by Marcus Jäger, Agnieszka Latosinska, Monika Herten, André Busch, Thomas Grupp and Andrea Sowislok

J. Funct. Biomater. 2022, 13(2), 44; https://doi.org/10.3390/jfb13020044 - 15 Apr 2022

Cited by 4 | Viewed by 3347

Abstract

Titanium implants are frequently applied to the bone in orthopedic and trauma surgery. Although these biomaterials are characterized by excellent implant survivorship and clinical outcomes, there are almost no data available on the initial protein layer binding to the implant surface in situ. [...] Read more.

Titanium implants are frequently applied to the bone in orthopedic and trauma surgery. Although these biomaterials are characterized by excellent implant survivorship and clinical outcomes, there are almost no data available on the initial protein layer binding to the implant surface in situ. This study aims to investigate the composition of the initial protein layer on endoprosthetic surfaces as a key initiating step in osseointegration. In patients qualified for total hip arthroplasty, the implants are inserted into the femoral canal, fixed and subsequently explanted after 2 and 5 min. The proteins adsorbed to the surface (the implant proteome) are analyzed by liquid chromatography–tandem mass spectrometry (LC-MS/MS). A statistical analysis of the proteins’ alteration with longer incubation times reveals a slight change in their abundance according to the Vroman effect. The pathways involved in the extracellular matrix organization of bone, sterile inflammation and the beginning of an immunogenic response governed by neutrophils are significantly enriched based on the analysis of the implant proteome. Those are generally not changed with longer incubation times. In summary, proteins relevant for osseointegration are already adsorbed within 2 min in situ. A deeper understanding of the in situ protein–implant interactions in patients may contribute to optimizing implant surfaces in orthopedic and trauma surgery. Full article

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

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22 pages, 5892 KiB

Open AccessEditor’s ChoiceArticle

TiO₂ Nanotubes Functionalized with Icariin for an Attenuated In Vitro Immune Response and Improved In Vivo Osseointegration

by Andreea-Mariana Negrescu, Valentina Mitran, Wanda Draghicescu, Simona Popescu, Cristian Pirvu, Iuliana Ionascu, Teodoru Soare, Seralp Uzun, Sorin Mihai Croitoru and Anisoara Cimpean

J. Funct. Biomater. 2022, 13(2), 43; https://doi.org/10.3390/jfb13020043 - 14 Apr 2022

Cited by 18 | Viewed by 3619

Abstract

Due to their superior mechanical and chemical properties, titanium (Ti) and its alloys have been widely used as orthopedic implantable devices. However, their bioinertness represents a limitation, which can be overcome by employing various surface modifications, such as TiO₂ nanotube (TNT) fabrication [...] Read more.

Due to their superior mechanical and chemical properties, titanium (Ti) and its alloys have been widely used as orthopedic implantable devices. However, their bioinertness represents a limitation, which can be overcome by employing various surface modifications, such as TiO₂ nanotube (TNT) fabrication via electrochemical anodization. Anodic TNTs present tunable dimensions and unique structures, turning them into feasible drug delivery platforms. In the present work, TNTs were loaded with icariin (Ica) through an adhesive intermediate layer of polydopamine (DP), and their in vitro and in vivo biological performance was evaluated. The successful fabrication of the modified surfaces was verified by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and contact angle measurements (CA), while the in vitro release of Ica was evaluated via UV-VIS spectrophotometry. In terms of in vitro behaviour, comparative studies on RAW 264.7 macrophages demonstrated that the TNT substrates, especially TNT-DP-Ica, elicited a lower inflammatory response compared to the Ti support. Moreover, the in vivo implantation studies evinced generation of a reduced fibrotic capsule around this implant and increased thickness of the newly formed bone tissue at 1 month and 3 months post-implantation, respectively. Overall, our results indicate that the controlled release of Ica from TNT surfaces could result in an improved osseointegration process. Full article

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

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12 pages, 1197 KiB

Open AccessEditor’s ChoiceArticle

Microbial Adhesion to Dental Polymers for Conventional, Computer-Aided Subtractive and Additive Manufacturing: A Comparative In Vitro Study

by Sergey Arutyunov, Levon Kirakosyan, Lubov Dubova, Yaser Kharakh, Nikolay Malginov, Gadzhi Akhmedov and Viktor Tsarev

J. Funct. Biomater. 2022, 13(2), 42; https://doi.org/10.3390/jfb13020042 - 11 Apr 2022

Cited by 19 | Viewed by 2988

Abstract

Modern structural materials are represented by a variety of polymer materials used for dental patients’ rehabilitation. They differ not only in physico-chemical properties, but also in microbiological properties, which is one of the reasons why these materials are chosen. The study focused on [...] Read more.

Modern structural materials are represented by a variety of polymer materials used for dental patients’ rehabilitation. They differ not only in physico-chemical properties, but also in microbiological properties, which is one of the reasons why these materials are chosen. The study focused on the microbial adhesion of clinical isolates of normal (5 types), periodontopathogenic (2 types), and fungal (2 types) microbiotas to various materials based on polymethylmethacrylate (PMMA) intended for traditional (cold-cured and hot-cured polymers), computer-aided subtractive and additive manufacturing. A comparative analysis was carried out on the studied samples of polymer materials according to the microorganisms’ adhesion index (AI). The lowest level of microorganisms’ AI of the three types of microbiotas was determined in relation to materials for additive manufacturing. The AI of hot-cured polymers, as well as materials for subtractive manufacturing, corresponded to the average level. The highest level of microorganisms’ adhesion was found in cold-cured polymers. Significant differences in AI for materials of the same technological production type (different manufacturers) were also determined. The tendency of significant differences in the indicators of the microorganisms’ adhesion level for the studied polymer materials on the basis of the type of production technology was determined. Full article

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23 pages, 3935 KiB

Open AccessEditor’s ChoiceReview

Printability and Cell Viability in Extrusion-Based Bioprinting from Experimental, Computational, and Machine Learning Views

by Ali Malekpour and Xiongbiao Chen

J. Funct. Biomater. 2022, 13(2), 40; https://doi.org/10.3390/jfb13020040 - 10 Apr 2022

Cited by 120 | Viewed by 11959

Abstract

Extrusion bioprinting is an emerging technology to apply biomaterials precisely with living cells (referred to as bioink) layer by layer to create three-dimensional (3D) functional constructs for tissue engineering. Printability and cell viability are two critical issues in the extrusion bioprinting process; printability [...] Read more.

Extrusion bioprinting is an emerging technology to apply biomaterials precisely with living cells (referred to as bioink) layer by layer to create three-dimensional (3D) functional constructs for tissue engineering. Printability and cell viability are two critical issues in the extrusion bioprinting process; printability refers to the capacity to form and maintain reproducible 3D structure and cell viability characterizes the amount or percentage of survival cells during printing. Research reveals that both printability and cell viability can be affected by various parameters associated with the construct design, bioinks, and bioprinting process. This paper briefly reviews the literature with the aim to identify the affecting parameters and highlight the methods or strategies for rigorously determining or optimizing them for improved printability and cell viability. This paper presents the review and discussion mainly from experimental, computational, and machine learning (ML) views, given their promising in this field. It is envisioned that ML will be a powerful tool to advance bioprinting for tissue engineering. Full article

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16 pages, 2847 KiB

Open AccessEditor’s ChoiceArticle

GelMA Hydrogel Reinforced with 3D Printed PEGT/PBT Scaffolds for Supporting Epigenetically-Activated Human Bone Marrow Stromal Cells for Bone Repair

by Kenny Man, Cesar Alcala, Naveen V. Mekhileri, Khoon S. Lim, Lin-Hua Jiang, Tim B. F. Woodfield and Xuebin B. Yang

J. Funct. Biomater. 2022, 13(2), 41; https://doi.org/10.3390/jfb13020041 - 10 Apr 2022

Cited by 10 | Viewed by 5568

Abstract

Epigenetic approaches using the histone deacetylase 2 and 3 inhibitor-MI192 have been reported to accelerate stem cells to form mineralised tissues. Gelatine methacryloyl (GelMA) hydrogels provide a favourable microenvironment to facilitate cell delivery and support tissue formation. However, their application for bone repair [...] Read more.

Epigenetic approaches using the histone deacetylase 2 and 3 inhibitor-MI192 have been reported to accelerate stem cells to form mineralised tissues. Gelatine methacryloyl (GelMA) hydrogels provide a favourable microenvironment to facilitate cell delivery and support tissue formation. However, their application for bone repair is limited due to their low mechanical strength. This study aimed to investigate a GelMA hydrogel reinforced with a 3D printed scaffold to support MI192-induced human bone marrow stromal cells (hBMSCs) for bone formation. Cell culture: The GelMA (5 wt%) hydrogel supported the proliferation of MI192-pre-treated hBMSCs. MI192-pre-treated hBMSCs within the GelMA in osteogenic culture significantly increased alkaline phosphatase activity (p ≤ 0.001) compared to control. Histology: The MI192-pre-treated group enhanced osteoblast-related extracellular matrix deposition and mineralisation (p ≤ 0.001) compared to control. Mechanical testing: GelMA hydrogels reinforced with 3D printed poly(ethylene glycol)-terephthalate/poly(butylene terephthalate) (PEGT/PBT) scaffolds exhibited a 1000-fold increase in the compressive modulus compared to the GelMA alone. MI192-pre-treated hBMSCs within the GelMA–PEGT/PBT constructs significantly enhanced extracellular matrix collagen production and mineralisation compared to control (p ≤ 0.001). These findings demonstrate that the GelMA–PEGT/PBT construct provides enhanced mechanical strength and facilitates the delivery of epigenetically-activated MSCs for bone augmentation strategies. Full article

(This article belongs to the Topic Advanced Functional Materials for Regenerative Medicine)

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14 pages, 2614 KiB

Open AccessEditor’s ChoiceArticle

TiO₂ Nanoparticles Dispersion in Block-Copolymer Aqueous Solutions: Nanoarchitectonics for Self-Assembly and Aggregation

by Valeria Conti Nibali, Giovanna D’Angelo, Antonella Arena, Carmine Ciofi, Graziella Scandurra and Caterina Branca

J. Funct. Biomater. 2022, 13(2), 39; https://doi.org/10.3390/jfb13020039 - 9 Apr 2022

Cited by 5 | Viewed by 3526

Abstract

Achieving homogenous dispersion of nanoparticles inside a polymeric matrix is a great challenge for numerous applications. In the present study, we aim at understanding the role of different factors on the dispersion properties of TiO₂ in pluronic F-127 mixtures. The mixtures were [...] Read more.

Achieving homogenous dispersion of nanoparticles inside a polymeric matrix is a great challenge for numerous applications. In the present study, we aim at understanding the role of different factors on the dispersion properties of TiO₂ in pluronic F-127 mixtures. The mixtures were prepared with different pH and guest/host ratios and investigated by UV-Vis spectroscopy, dynamic light scattering, infrared spectroscopy and electrical conductivity. Depending on the preparation conditions, different amounts of TiO₂ were loaded within the copolymer as quantitatively determined by UV-Vis spectroscopy. The different content of nanoparticles has direct implications on the gelation and micellization of pluronic analyzed by dynamic light scattering. The information derived on the self-assembly behavior was interpreted in relation to the infrared and conductivity measurements results. Together, these results shed light on the most favorable conditions for improving the nanoparticle dispersion inside the copolymer matrix and suggest a possible strategy to design functional nanoparticle-polymer systems. Full article

(This article belongs to the Topic Nanoarchitectonics with Molecular and Materials Science: Functional Materials for Energy, Environment, Bio and Others)

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18 pages, 2501 KiB

Open AccessEditor’s ChoiceSystematic Review

Clinical and Radiographic Outcome of Non-Surgical Endodontic Treatment Using Calcium Silicate-Based Versus Resin-Based Sealers—A Systematic Review and Meta-Analysis of Clinical Studies

by Viresh Chopra, Graham Davis and Aylin Baysan

J. Funct. Biomater. 2022, 13(2), 38; https://doi.org/10.3390/jfb13020038 - 7 Apr 2022

Cited by 10 | Viewed by 5337

Abstract

The aim of this paper is to systematically analyse the effect of calcium silicate-based sealers in comparison to resin-based sealers on clinical and radiographic outcomes of non-surgical endodontic treatment in permanent teeth. Methods: The study was conducted according to the guidelines of the [...] Read more.

The aim of this paper is to systematically analyse the effect of calcium silicate-based sealers in comparison to resin-based sealers on clinical and radiographic outcomes of non-surgical endodontic treatment in permanent teeth. Methods: The study was conducted according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. The literature search was performed using PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, DOAJ and OpenGrey with no language restrictions. Two reviewers critically assessed the studies for eligibility. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was carried out to assess the evidence. Meta-analysis of the pooled data with subgroups was carried out using the RevMan software (p < 0.05). Results: Results from the included studies showed that there were no significant differences between the groups in the 24 h post-obturation pain levels (mean difference (MD), −0.19, 95% CI = −0.43–0.06, p = 0.14, I² = 0%), but at 48 h (MD, −0.35, 95% CI = −0.64–0.05, p = 0.02, I² = 0%), a significant difference was observed in favour of calcium silicate sealers. Furthermore, there were no significant differences between the two sealers due to risk of onset or intensity of postoperative pain, need for analgesic and extrusion of the sealer. The heterogeneity assessed using Q test between the included studies was 97% (I²). Conclusions: Within the limitations of this review, the paper shows that calcium silicate-based sealers exhibited optimal performance with similar results to resin-based sealers in terms of average level of post-obturation pain, risk of onset and pain intensity at 24 and 48 h. The observations from the included studies are informative in the clinical evaluation of calcium silicate-based sealers and provide evidence for the conduction of well-designed, controlled randomised clinical trials for a period of at least four years in the future. Full article

(This article belongs to the Special Issue Endodontic Biomaterials)

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15 pages, 2106 KiB

Open AccessEditor’s ChoiceArticle

HexA-Enzyme Coated Polymer Nanoparticles for the Development of a Drug-Delivery System in the Treatment of Sandhoff Lysosomal Storage Disease

by Eleonora Calzoni, Alessio Cesaretti, Nicolò Montegiove, Alessandro Di Michele, Roberto Maria Pellegrino and Carla Emiliani

J. Funct. Biomater. 2022, 13(2), 37; https://doi.org/10.3390/jfb13020037 - 31 Mar 2022

Cited by 8 | Viewed by 3530

Abstract

Lysosomal storage disorders (LSDs) are a set of metabolic diseases caused by mutations in genes that are in charge of the production of lysosomal enzymes, resulting in the buildup of non-degraded substrates and the consequent systemic damage that mainly involves the Central Nervous [...] Read more.

Lysosomal storage disorders (LSDs) are a set of metabolic diseases caused by mutations in genes that are in charge of the production of lysosomal enzymes, resulting in the buildup of non-degraded substrates and the consequent systemic damage that mainly involves the Central Nervous System (CNS). One of the most widely used and studied treatments is Enzyme Replacement Therapy, which is based on the administration of the recombinant deficient enzyme. This strategy has often proved fallacious due to the enzyme instability in body fluids and its inability to reach adequate levels in the CNS. In this work, we developed a system based on nanotechnology that allows a stable enzyme to be obtained by its covalent immobilization on nanoparticles (NPs) of polylactic acid, subsequently administered to a cellular model of LSDs, i.e., Sandhoff disease, caused by the absence or deficiency of the β-d-N-acetyl-hexosaminidase A (HexA) enzyme. The HexA enzymes, loaded onto the polymeric NPs through an immobilization procedure that has already been investigated and validated, were found to be stable over time, maintain optimal kinetic parameters, be able to permeate the plasma membrane, hydrolyze HexA’s natural substrate, and restore enzyme activity close to the levels of healthy cells. These results thus lay the foundation for testing the HexA-NPs in animal models of the disease and thus obtaining an efficient drug-delivery system. Full article

(This article belongs to the Special Issue Biomaterials for Drug Delivery)

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11 pages, 21197 KiB

Open AccessEditor’s ChoiceArticle

Uncovering Novel Pre-Treatment Molecular Biomarkers for Anti-TNF Therapeutic Response in Patients with Crohn’s Disease

by Min Seob Kwak, Jae Myung Cha, Jung Won Jeon, Jin Young Yoon and Su Bee Park

J. Funct. Biomater. 2022, 13(2), 36; https://doi.org/10.3390/jfb13020036 - 30 Mar 2022

Cited by 5 | Viewed by 3457

Abstract

Neutralising monoclonal antibodies for tumour necrosis factor (TNF) has been widely used to treat Crohn’s disease (CD) in clinical practice. However, differential individual response necessitates a therapeutic response assessment of anti-TNF agents in CD patients for optimizing therapeutic strategy. We aimed to predict [...] Read more.

Neutralising monoclonal antibodies for tumour necrosis factor (TNF) has been widely used to treat Crohn’s disease (CD) in clinical practice. However, differential individual response necessitates a therapeutic response assessment of anti-TNF agents in CD patients for optimizing therapeutic strategy. We aimed to predict anti-TNF therapy response in CD patients using transcriptome analyses. Transcriptome analyses were performed using data from the Gene Expression Omnibus, GeneCards, and Human Protein Atlas databases. The significantly mitigated biological functions associated with anti-TNF therapy resistance in CD patients encompassed immune pathways, including Interleukin-17 (IL-17) signaling, cytokine-cytokine receptor interaction, and rheumatoid arthritis. The scores of immune cell markers, including neutrophils, monocytes, and macrophages/monocytes were also significantly decreased in non-responders compared with that measured in anti-TNF therapy responders. The KAT2B gene, associated with IL-17 cytokine mediated neutrophil mobilization and activation, was significantly under-expressed in both tissue and peripheral blood mononuclear cells (PBMCs) in anti-TNF therapy-resistant CD patients. The reduced expression of several pro-inflammatory cytokines due to down-regulated IL-17 signaling, is suggestive of the primary non-response to anti-TNF agents in CD patients. Furthermore, the PBMC KAT2B gene signature may be a promising pre-treatment prognostic biomarker for anti-TNF drug response in CD patients. Full article

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13 pages, 3285 KiB

Open AccessEditor’s ChoiceArticle

Engineering 3D Printed Scaffolds with Tunable Hydroxyapatite

by Yoontae Kim, Eun-Jin Lee, Anthony P. Kotula, Shozo Takagi, Laurence Chow and Stella Alimperti

J. Funct. Biomater. 2022, 13(2), 34; https://doi.org/10.3390/jfb13020034 - 23 Mar 2022

Cited by 13 | Viewed by 5870

Abstract

Orthopedic and craniofacial surgical procedures require the reconstruction of bone defects caused by trauma, diseases, and tumor resection. Successful bone restoration entails the development and use of bone grafts with structural, functional, and biological features similar to native tissues. Herein, we developed three-dimensional [...] Read more.

Orthopedic and craniofacial surgical procedures require the reconstruction of bone defects caused by trauma, diseases, and tumor resection. Successful bone restoration entails the development and use of bone grafts with structural, functional, and biological features similar to native tissues. Herein, we developed three-dimensional (3D) printed fine-tuned hydroxyapatite (HA) biomimetic bone structures, which can be applied as grafts, by using calcium phosphate cement (CPC) bioink, which is composed of tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA), and a liquid [Polyvinyl butyral (PVB) dissolved in ethanol (EtOH)]. The ink was ejected through a high-resolution syringe nozzle (210 µm) at room temperature into three different concentrations (0.01, 0.1, and 0.5) mol/L of the aqueous sodium phosphate dibasic (Na₂HPO₄) bath that serves as a hardening accelerator for HA formation. Raman spectrometer, X-ray diffraction (XRD), and scanning electron microscopy (SEM) demonstrated the real-time HA formation in (0.01, 0.1, and 0.5) mol/L Na₂HPO₄ baths. Under those conditions_, HA was formed at different amounts, which tuned the scaffolds’ mechanical properties, porosity, and osteoclast activity. Overall, this method may pave the way to engineer 3D bone scaffolds with controlled HA composition and pre-defined properties, which will enhance graft-host integration in various anatomic locations. Full article

(This article belongs to the Special Issue Smart Biomaterials for Soft and Hard Tissue Repair and Regeneration)

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16 pages, 4402 KiB

Open AccessEditor’s ChoiceArticle

Synergistic Antibacterial Effect of Zinc Oxide Nanoparticles and Polymorphonuclear Neutrophils

by Kai Ye, Moran Huang, Xiaojian He, Zhiquan An and Hui Qin

J. Funct. Biomater. 2022, 13(2), 35; https://doi.org/10.3390/jfb13020035 - 23 Mar 2022

Cited by 7 | Viewed by 4050

Abstract

Zinc oxide nanoparticles (ZnONPs) are inorganic nano-biomaterials with excellent antimicrobial properties. However, their effects on the anti-infection ability of the innate immune system remains poorly understood. The aim of the present study was to explore the potential immunomodulatory effects of ZnONPs on the [...] Read more.

Zinc oxide nanoparticles (ZnONPs) are inorganic nano-biomaterials with excellent antimicrobial properties. However, their effects on the anti-infection ability of the innate immune system remains poorly understood. The aim of the present study was to explore the potential immunomodulatory effects of ZnONPs on the innate immune system, represented by polymorphonuclear leukocytes (PMNs), and determine whether they can act synergistically to resist pathogen infections. In vitro experiment showed that ZnONPs not only exhibit obvious antibacterial activity at biocompatible concentrations but also enhance the antibacterial property of PMNs. In vivo experiments demonstrated the antibacterial effect of ZnONPs, accompanied by more infiltration of subcutaneous immune cells. Further ex vivo and in vitro experiments revealed that ZnONPs enhanced the migration of PMNs, promoted their bacterial phagocytosis efficiency, proinflammatory cytokine (TNF-α, IL-1β, and IL-6) expression, and reactive oxygen species (ROS) production. In summary, this study revealed potential synergistic effects of ZnONPs on PMNs to resist pathogen infection and the underlying mechanisms. The findings suggest that attempts should be made to fabricate and apply biomaterials in order to maximize their synergy with the innate immune system, thus promoting the host’s resistance to pathogen invasion. Full article

(This article belongs to the Special Issue State-of-the-Art Functional Biomaterials in China)

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11 pages, 1152 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Dental Poly(methyl methacrylate)-Based Resin Containing a Nanoporous Silica Filler

by Kentaro Hata, Hiroshi Ikeda, Yuki Nagamatsu, Chihiro Masaki, Ryuji Hosokawa and Hiroshi Shimizu

J. Funct. Biomater. 2022, 13(1), 32; https://doi.org/10.3390/jfb13010032 - 15 Mar 2022

Cited by 19 | Viewed by 4523

Abstract

Poly(methyl methacrylate) (PMMA)-based resins have been conventionally used in dental prostheses owing to their good biocompatibility. However, PMMA-based resins have relatively poor mechanical properties. In the present study, a novel nanoporous silica filler was developed and introduced into PMMA-based resins to improve their [...] Read more.

Poly(methyl methacrylate) (PMMA)-based resins have been conventionally used in dental prostheses owing to their good biocompatibility. However, PMMA-based resins have relatively poor mechanical properties. In the present study, a novel nanoporous silica filler was developed and introduced into PMMA-based resins to improve their mechanical properties. The filler was prepared by sintering a green body composed of silica and an organic binder, followed by grinding to a fine powder and subsequent silanization. The filler was added to photocurable PMMA-based resin, which was prepared from MMA, PMMA, ethylene glycol dimethacrylate, and a photo-initiator. The filler was characterized by scanning electron microscopy (SEM), X-ray diffraction analysis, nitrogen sorption porosimetry, and Fourier transform infrared (FT-IR) spectroscopy. The PMMA-based resins were characterized by SEM and FT-IR, and the mechanical properties (Vickers hardness, flexural modulus, and flexural strength) and physicochemical properties (water sorption and solubility) were evaluated. The results suggested that the filler consisted of microparticles with nanopores. The filler at 23 wt % was well dispersed in the PMMA-based resin matrix. The mechanical and physicochemical properties of the PMMA-based resin improved significantly with the addition of the developed filler. Therefore, such filler-loaded PMMA-based resins are potential candidates for improving the strength and durability of polymer-based crown and denture base. Full article

(This article belongs to the Special Issue Feature Papers in Dental Biomaterials)

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14 pages, 21377 KiB

Open AccessEditor’s ChoiceArticle

Engineering Nanopatterned Structures to Orchestrate Macrophage Phenotype by Cell Shape

by Kai Li, Lin Lv, Dandan Shao, Youtao Xie, Yunzhen Cao and Xuebin Zheng

J. Funct. Biomater. 2022, 13(1), 31; https://doi.org/10.3390/jfb13010031 - 14 Mar 2022

Cited by 20 | Viewed by 4051

Abstract

Physical features on the biomaterial surface are known to affect macrophage cell shape and phenotype, providing opportunities for the design of novel “immune-instructive” topographies to modulate foreign body response. The work presented here employed nanopatterned polydimethylsiloxane substrates with well-characterized nanopillars and nanopits to [...] Read more.

Physical features on the biomaterial surface are known to affect macrophage cell shape and phenotype, providing opportunities for the design of novel “immune-instructive” topographies to modulate foreign body response. The work presented here employed nanopatterned polydimethylsiloxane substrates with well-characterized nanopillars and nanopits to assess RAW264.7 macrophage response to feature size. Macrophages responded to the small nanopillars (SNPLs) substrates (450 nm in diameter with average 300 nm edge-edge spacing), resulting in larger and well-spread cell morphology. Increasing interpillar distance to 800 nm in the large nanopillars (LNPLs) led to macrophages exhibiting morphologies similar to being cultured on the flat control. Macrophages responded to the nanopits (NPTs with 150 nm deep and average 800 nm edge-edge spacing) by a significant increase in cell elongation. Elongation and well-spread cell shape led to expression of anti-inflammatory/pro-healing (M2) phenotypic markers and downregulated expression of inflammatory cytokines. SNPLs and NPTs with high availability of integrin binding region of fibronectin facilitated integrin β1 expression and thus stored focal adhesion formation. Increased integrin β1 expression in macrophages on the SNPLs and NTPs was required for activation of the PI3K/Akt pathway, which promoted macrophage cell spreading and negatively regulated NF-κB activation as evidenced by similar globular cell shape and higher level of NF-κB expression after PI3K blockade. These observations suggested that alterations in macrophage cell shape from surface nanotopographies may provide vital cues to orchestrate macrophage phenotype. Full article

(This article belongs to the Special Issue Feature Papers in Bone Biomaterials)

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11 pages, 2200 KiB

Open AccessEditor’s ChoiceArticle

Surface Properties of Ti6Al7Nb Alloy: Surface Free Energy and Bacteria Adhesion

by Monika Krzywicka, Jolanta Szymańska, Szymon Tofil, Anna Malm and Agnieszka Grzegorczyk

J. Funct. Biomater. 2022, 13(1), 26; https://doi.org/10.3390/jfb13010026 - 7 Mar 2022

Cited by 11 | Viewed by 3534

Abstract

The laser micro-machining was carried out on a station equipped with a TruMicro 5325c laser emitting ultraviolet radiation (343 nm wavelength) in picosecond pulses. On the surface of the Ti6Al7Nb alloy, dimple texturing with a constant diameter of ~200 μm, different depths (from [...] Read more.

The laser micro-machining was carried out on a station equipped with a TruMicro 5325c laser emitting ultraviolet radiation (343 nm wavelength) in picosecond pulses. On the surface of the Ti6Al7Nb alloy, dimple texturing with a constant diameter of ~200 μm, different depths (from ~5 to ~78 μm) and density (from 10% to 50%) were produced. The value of surface free energy was determined with the Owens–Wendt method using two measuring liquids: distilled water and diodomethane. The Staphylococcus epidermidis strain was used to test the adhesion of bacteria. It was found that the surface free energy value is influenced by both of the texture parameters (density, depth). The density also affects the potential for biofilm formation. Based on the analysis, it was shown that with an increase in surface free energy, the number of adhering microorganisms increases exponentially. Moreover, the study shows that there is a correlation between the number of adhering microorganisms and surface free energy. Full article

(This article belongs to the Topic Materials in Implant Applications and Regenerative Medicine)

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16 pages, 4996 KiB

Open AccessEditor’s ChoiceArticle

Osseointegration at Implants Installed in Composite Bone: A Randomized Clinical Trial on Sinus Floor Elevation

by Mitsuo Kotsu, Karol Alí Apaza Alccayhuaman, Mauro Ferri, Giovanna Iezzi, Adriano Piattelli, Natalia Fortich Mesa and Daniele Botticelli

J. Funct. Biomater. 2022, 13(1), 22; https://doi.org/10.3390/jfb13010022 - 28 Feb 2022

Cited by 9 | Viewed by 3184

Abstract

Osseointegration of implants installed in conjunction with sinus floor elevation might be affected by the presence of residual graft. The implant surface characteristics and the protection of the access window using a collagen membrane might influence the osseointegration. To evaluate these factors, sinus [...] Read more.

Osseointegration of implants installed in conjunction with sinus floor elevation might be affected by the presence of residual graft. The implant surface characteristics and the protection of the access window using a collagen membrane might influence the osseointegration. To evaluate these factors, sinus floor elevation was performed in patients using a natural bovine bone grafting material. The access windows were either covered with a collagen membrane made of porcine corium (Mb group) or left uncovered (No-Mb group) and, after six months, two mini-implants with either a moderate rough or turned surfaces were installed. After 3 months, biopsies containing the mini-implants were retrieved, processed histologically, and analyzed. Twenty patients, ten in each group, were included in the study. The two mini-implants were retrieved from fourteen patients, six belonging to the Mb group, and eight to the No-Mb group. No statistically significant differences were found in osseointegration between groups. However, statistically significant differences were found between the two surfaces. It was concluded that implants with a moderately rough surface installed in a composite bone presented much higher osseointegration compared to those with a turned surface. The present study failed to show an effect of the use of a collagen membrane on the access window. Full article

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

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18 pages, 28499 KiB

Open AccessEditor’s ChoiceArticle

The Comparison of Advanced Electrospun Materials Based on Poly(-3-hydroxybutyrate) with Natural and Synthetic Additives

by Polina Tyubaeva, Ivetta Varyan, Alexey Krivandin, Olga Shatalova, Svetlana Karpova, Anton Lobanov, Anatoly Olkhov and Anatoly Popov

J. Funct. Biomater. 2022, 13(1), 23; https://doi.org/10.3390/jfb13010023 - 28 Feb 2022

Cited by 8 | Viewed by 2983

Abstract

The comparison of the effect of porphyrins of natural and synthetic origin containing the same metal atom on the structure and properties of the semi-crystalline polymer matrix is of current concern. A large number of modifying additives and biodegradable polymers for biomedical purposes, [...] Read more.

The comparison of the effect of porphyrins of natural and synthetic origin containing the same metal atom on the structure and properties of the semi-crystalline polymer matrix is of current concern. A large number of modifying additives and biodegradable polymers for biomedical purposes, composed of poly(-3-hydroxybutyrate)-porphyrin, are of particular interest because of the combination of their unique properties. The objective of this work are electrospun fibrous material based on poly(-3-hydroxybutyrate) (PHB), hemin (Hmi), and tetraphenylporphyrin with iron (Fe(TPP)Cl). The structure of these new materials was investigated by methods such as optical and scanning electron microscopy, X-ray diffraction analysis, Electron paramagnetic resonance method, and Differential scanning calorimetry. The properties of the electrospun materials were analyzed by mechanical and biological tests, and the wetting contact angle was measured. In this work, it was found that even small concentrations of porphyrin can increase the antimicrobial properties by 12 times, improve the physical and mechanical properties by at least 3.5 times, and vary hydrophobicity by at least 5%. At the same time, additives similar in the structure had an oppositely directed effect on the supramolecular structure, the composition of the crystalline, and the amorphous phases. The article considers assumptions about the nature of such differences due to the influence of Hmi and Fe(TPP)Cl) on the macromolecular and fibrous structure of PHB. Full article

(This article belongs to the Special Issue Biodegradable Polymers and Textiles)

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17 pages, 4891 KiB

Open AccessEditor’s ChoiceArticle

Multi-Stimulus Responsive Multilayer Coating for Treatment of Device-Associated Infections

by Wenlong Li, Guanping Hua, Jingfeng Cai, Yaming Zhou, Xi Zhou, Miao Wang, Xiumin Wang, Baoqing Fu and Lei Ren

J. Funct. Biomater. 2022, 13(1), 24; https://doi.org/10.3390/jfb13010024 - 28 Feb 2022

Cited by 18 | Viewed by 5304

Abstract

Antibacterial coating with antibiotics is highly effective in avoiding device-associated infections (DAIs) which is an unsolved healthcare problem that causes significant morbidity and mortality rates. However, bacterial drug resistance caused by uncontrolled release of antibiotics seriously restricts clinical efficacy of antibacterial coating. Hence, [...] Read more.

Antibacterial coating with antibiotics is highly effective in avoiding device-associated infections (DAIs) which is an unsolved healthcare problem that causes significant morbidity and mortality rates. However, bacterial drug resistance caused by uncontrolled release of antibiotics seriously restricts clinical efficacy of antibacterial coating. Hence, a local and controlled-release system which can release antibiotics in response to bacterial infected signals is necessary in antibacterial coating. Herein, a multi-stimulus responsive multilayer antibacterial coating was prepared through layer-by-layer (LbL) self-assembly of montmorillonite (MMT), chlorhexidine acetate (CHA) and Poly(protocatechuic acid-polyethylene glycol 1000-bis(phenylboronic acid carbamoyl) cystamine) (PPPB). The coating can be covered on various substrates such as cellulose acetate membrane, polyacrylonitrile membrane, polyvinyl chloride membrane, and polyurethane membrane, proving it is a versatile coating. Under the stimulation of acids, glucose or dithiothreitol, this coating was able to achieve controlled release of CHA and kill more than 99% of Staphylococcus aureus and Escherichia coli (4 × 10⁸ CFU/mL) within 4 h. In the mouse infection model, CHA releasing of the coating was triggered by infected microenvironment to completely kill bacteria, achieving wounds healing within 14 days. Full article

(This article belongs to the Special Issue State-of-the-Art Functional Biomaterials in China)

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16 pages, 3136 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Degradation of Dental Methacrylate-Based Composites in Simulated Clinical Immersion Media

by Nicoleta Ilie

J. Funct. Biomater. 2022, 13(1), 25; https://doi.org/10.3390/jfb13010025 - 28 Feb 2022

Cited by 9 | Viewed by 2968

Abstract

The selection of restorative materials with regard to the longevity and durability of a restoration is of crucial importance for daily dental practice and requires that the degradation of the material in the oral environment can be assessed. The aim of this study [...] Read more.

The selection of restorative materials with regard to the longevity and durability of a restoration is of crucial importance for daily dental practice and requires that the degradation of the material in the oral environment can be assessed. The aim of this study was to investigate the extent to which the mechanical properties of four (Esthet X, Ceram X, Filtek Supreme XT, and Filtek Supreme XT flow) resin-based composites (RBCs) alter during storage in saliva substitutes (artificial saliva) for 24 h and 28 days and in the context of simulated, more aggressive clinical conditions, including cycles exposure to de- and remineralization, alcohol, or salivary enzymes. For this purpose, flexural strength and modulus were determined in a three-point bending test (n = 20) followed by Weibull analysis, while quasi-static behavior was evaluated by instrumented indentation techniques. Degradation occurred in all RBCs and all aging protocols and was quantifiable at both macroscopic and microscopic levels. The postulated stabilizing effect on degradation through the incorporation of urethane-based co-monomers into the organic matrix or a higher filler loading is refuted. Even though modern RBCs show high clinical survival rates, biodegradation remains an issue that needs to be addressed. Full article

(This article belongs to the Section Dental Biomaterials)

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17 pages, 5826 KiB

Open AccessEditor’s ChoiceArticle

SpAD Biofunctionalized Cellulose Acetate Scaffolds Inhibit Staphylococcus aureus Adherence in a Coordinating Function with the von Willebrand A1 Domain (vWF A1)

by Stefanos Pendas, Antonis Asiminas, Alexandros Katranidis, Costas Tsioptsias, Maria Pitou, Georgios Papadopoulos and Theodora Choli-Papadopoulou

J. Funct. Biomater. 2022, 13(1), 21; https://doi.org/10.3390/jfb13010021 - 21 Feb 2022

Cited by 2 | Viewed by 3073

Abstract

Staphylococcus aureus is one of the major pathogens causing and spreading hospital acquired infections. Since it is highly resistant to new generation antibiotics, novel strategies have to be developed such as the construction of biofunctionalized non-adherent surfaces that will prevent its tethering and [...] Read more.

Staphylococcus aureus is one of the major pathogens causing and spreading hospital acquired infections. Since it is highly resistant to new generation antibiotics, novel strategies have to be developed such as the construction of biofunctionalized non-adherent surfaces that will prevent its tethering and subsequent spread in the hospital environment. In this frame, the domain D of protein A (SpAD) of S. aureus has been immobilized onto cellulose acetate scaffolds by using the streptavidin/biotin interaction, in order to study its interaction with the A1 domain of von Willebrand factor (vWF A1), a protein essential for hemostasis, found in human plasma. Subsequently, the biofunctionalized cellulose acetate scaffolds were incubated with S. aureus in the presence and absence of vWF A1 at different time periods and their potential to inhibit S. aureus growth was studied with scanning electron microscopy (SEM). The SpAD biofunctionalized scaffolds perceptibly ameliorated the non-adherent properties of the material, and in particular, the interaction between SpAD and vWF A1 effectively inhibited the growth of S. aureus. Thus, the exhibition of significant non-adherent properties of scaffolds addresses their potential use for covering medical equipment, implants, and stents. Full article

(This article belongs to the Special Issue Cell Tissue Engineering and the Lung)

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14 pages, 3029 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Low-Modulus PMMA Has the Potential to Reduce Stresses on Endplates after Cement Discoplasty

by Susanne Lewin, Peter Försth and Cecilia Persson

J. Funct. Biomater. 2022, 13(1), 18; https://doi.org/10.3390/jfb13010018 - 4 Feb 2022

Cited by 16 | Viewed by 4090

Abstract

Cement discoplasty has been developed to treat patients with advanced intervertebral disc degeneration. In discoplasty, poly(methylmethacrylate) (PMMA) bone cement is injected into the disc, leading to reduced pain and certain spinal alignment correction. Standard PMMA-cements have much higher elastic modulus than the surrounding [...] Read more.

Cement discoplasty has been developed to treat patients with advanced intervertebral disc degeneration. In discoplasty, poly(methylmethacrylate) (PMMA) bone cement is injected into the disc, leading to reduced pain and certain spinal alignment correction. Standard PMMA-cements have much higher elastic modulus than the surrounding vertebral bone, which may lead to a propensity for adjacent fractures. A PMMA-cement with lower modulus might be biomechanically beneficial. In this study, PMMA-cements with lower modulus were obtained using previously established methods. A commercial PMMA-cement (V-steady^®, G21 srl) was used as control, and as base cement. The low-modulus PMMA-cements were modified by 12 vol% (LA12), 16 vol% (LA16) and 20 vol% (LA20) linoleic acid (LA). After storage in 37 °C PBS from 24 h up to 8 weeks, specimens were tested in compression to obtain the material properties. A lower E-modulus was obtained with increasing amount of LA. However, with storage time, the E-modulus increased. Standard and low-modulus PMMA discoplasty were compared in a previously developed and validated computational lumbar spine model. All discoplasty models showed the same trend, namely a substantial reduction in range of motion (ROM), compared to the healthy model. The V-steady model had the largest ROM-reduction (77%), and the LA20 model had the smallest (45%). The average stress at the endplate was higher for all discoplasty models than for the healthy model, but the stresses were reduced for cements with higher amounts of LA. The study indicates that low-modulus PMMA is promising for discoplasty from a mechanical viewpoint. However, validation experiments are needed, and the clinical setting needs to be further considered. Full article

(This article belongs to the Special Issue Experimentation, Numerical and Analytical Methods in Functional Biomaterials)

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12 pages, 2912 KiB

Open AccessEditor’s ChoiceArticle

Effect of Gamma Irradiation on the Osteoinductivity of Demineralized Dentin Matrix for Allografts: A Preliminary Study

by Jeong-Kui Ku, Il-hyung Kim, In-Woong Um, Bo-Hyun Kim and Pil-Young Yun

J. Funct. Biomater. 2022, 13(1), 14; https://doi.org/10.3390/jfb13010014 - 31 Jan 2022

Cited by 7 | Viewed by 3913

Abstract

Demineralized dentin matrix (DDM) treated with gamma irradiation (GR) has shown promising results as an allograft without any adverse effects in in vivo and clinical studies. The purpose of this study was to evaluate the effects of 15 and 25 kGy GR on [...] Read more.

Demineralized dentin matrix (DDM) treated with gamma irradiation (GR) has shown promising results as an allograft without any adverse effects in in vivo and clinical studies. The purpose of this study was to evaluate the effects of 15 and 25 kGy GR on the osteoinductive properties of DDM at extra-skeletal sites. As a control group, non-irradiated DDM powder was implanted into the right subcutaneous tissues of the dorsal thigh muscles of 20 nude mice. DDM powder irradiated with 15 and 25 kGy was implanted into the left side. After two and four weeks, the bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry. After confirming osteoblast- and osteoclast-specific activities by alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) staining, a histological analysis was performed to measure the new bone formation and the number of osteoblasts and osteoclast-like cells on the surface of the DDMs. Histomorphometry was used to calculate the new bone formation area on the surface of the DDM particles (DDMs). The BMD in all the groups increased from two and four weeks without statistically significant differences. The osteoblasts were dominantly activated on DDM without GR, and DDM treated with 25 kGy compared to DDM treated with 15 kGy. Among the groups, new bone formation was identified in all the groups at each time point. In conclusion, GR at doses of 15 and 25 kGy does not affect the osteoinductive properties of DDM powder. Full article

(This article belongs to the Special Issue Application of Dentin Matrix in Tissue Regeneration)

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25 pages, 11491 KiB

Open AccessEditor’s ChoiceArticle

Biomimetic PLGA/Strontium-Zinc Nano Hydroxyapatite Composite Scaffolds for Bone Regeneration

by Mozan Hassan, Mohsin Sulaiman, Priya Dharshini Yuvaraju, Emmanuel Galiwango, Ihtesham ur Rehman, Ali H. Al-Marzouqi, Abbas Khaleel and Sahar Mohsin

J. Funct. Biomater. 2022, 13(1), 13; https://doi.org/10.3390/jfb13010013 - 28 Jan 2022

Cited by 30 | Viewed by 8913

Abstract

Synthetic bone graft substitutes have attracted increasing attention in tissue engineering. This study aimed to fabricate a novel, bioactive, porous scaffold that can be used as a bone substitute. Strontium and zinc doped nano-hydroxyapatite (Sr/Zn n-HAp) were synthesized by a water-based sol-gel technique. [...] Read more.

Synthetic bone graft substitutes have attracted increasing attention in tissue engineering. This study aimed to fabricate a novel, bioactive, porous scaffold that can be used as a bone substitute. Strontium and zinc doped nano-hydroxyapatite (Sr/Zn n-HAp) were synthesized by a water-based sol-gel technique. Sr/Zn n-HAp and poly (lactide-co-glycolide) (PLGA) were used to fabricate composite scaffolds by supercritical carbon dioxide technique. FTIR, XRD, TEM, SEM, and TGA were used to characterize Sr/Zn n-HAp and the composite scaffolds. The synthesized scaffolds were adequately porous with an average pore size range between 189 to 406 µm. The scaffolds demonstrated bioactive behavior by forming crystals when immersed in the simulated body fluid. The scaffolds after immersing in Tris/HCl buffer increased the pH value of the medium, establishing their favorable biodegradable behavior. ICP-MS study for the scaffolds detected the presence of Sr, Ca, and Zn ions in the SBF within the first week, which would augment osseointegration if implanted in the body. nHAp and their composites (PLGA-nHAp) showed ultimate compressive strength ranging between 0.4–19.8 MPa. A 2.5% Sr/Zn substituted nHAp-PLGA composite showed a compressive behavior resembling that of cancellous bone indicating it as a good candidate for cancellous bone substitute. Full article

(This article belongs to the Special Issue Smart Biomaterials for Soft and Hard Tissue Repair and Regeneration)

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11 pages, 3070 KiB

Open AccessEditor’s ChoiceArticle

Preliminary Results on Heparin-Modified Double-Layered PCL and PLA-Based Scaffolds for Tissue Engineering of Small Blood Vessels

by Patrycja Domalik-Pyzik and Anna Morawska-Chochół

J. Funct. Biomater. 2022, 13(1), 11; https://doi.org/10.3390/jfb13010011 - 27 Jan 2022

Cited by 6 | Viewed by 3497

Abstract

Low-diameter blood vessels are challenging to replace with more traditional synthetic vascular grafts. Therefore, the obvious choice is to try to regenerate small veins and arteries through tissue-engineering approaches. However, the layered structure of native vessels and blood compatibility issues make this a [...] Read more.

Low-diameter blood vessels are challenging to replace with more traditional synthetic vascular grafts. Therefore, the obvious choice is to try to regenerate small veins and arteries through tissue-engineering approaches. However, the layered structure of native vessels and blood compatibility issues make this a very challenging task. The aim of this study is to create double-layered tubular scaffolds with enhanced anticoagulant properties for the tissue engineering of small blood vessels. The scaffolds were made of a polycaprolactone-based porous outer layer and a polylactide-based electrospun inner layer modified with heparin. The combination of thermally induced phase separation and electrospinning resulted in asymmetric scaffolds with improved mechanical properties. The release assay confirmed that heparin is released from the scaffolds. Additionally, anticoagulant activity was shown through APTT (activated partial thromboplastin time) assay. Interestingly, the endothelial cell culture test revealed that after 14 days of culture, HAECs (human aortic endothelial cell lines) tended to organize in chain-like structures, typical for early stages of vascular formation. In the longer culture, HAEC viability was higher for the heparin-modified scaffolds. The proposed scaffold design and composition have great potential for application in tissue engineering of small blood vessels. Full article

(This article belongs to the Special Issue Bioinspired Materials for Medical and Biotechnological Applications)

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11 pages, 8011 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

3D Printing of Hierarchically Porous Lattice Structures Based on Åkermanite Glass Microspheres and Reactive Silicone Binder

by Arish Dasan, Jozef Kraxner, Luca Grigolato, Gianpaolo Savio, Hamada Elsayed, Dušan Galusek and Enrico Bernardo

J. Funct. Biomater. 2022, 13(1), 8; https://doi.org/10.3390/jfb13010008 - 13 Jan 2022

Cited by 10 | Viewed by 4687

Abstract

The present study illustrates the manufacturing method of hierarchically porous 3D scaffolds based on åkermanite as a promising bioceramic for stereolithography. The macroporosity was designed by implementing 3D models corresponding to different lattice structures (cubic, diamond, Kelvin, and Kagome). To obtain micro-scale porosity, [...] Read more.

The present study illustrates the manufacturing method of hierarchically porous 3D scaffolds based on åkermanite as a promising bioceramic for stereolithography. The macroporosity was designed by implementing 3D models corresponding to different lattice structures (cubic, diamond, Kelvin, and Kagome). To obtain micro-scale porosity, flame synthesized glass microbeads with 10 wt% of silicone resins were utilized to fabricate green scaffolds, later converted into targeted bioceramic phase by firing at 1100 °C in air. No chemical reaction between the glass microspheres, crystallizing into åkermanite, and silica deriving from silicone oxidation was observed upon heat treatment. Silica acted as a binder between the adjacent microspheres, enhancing the creation of microporosity, as documented by XRD, and SEM coupled with EDX analysis. The formation of ‘spongy’ struts was confirmed by infiltration with Rhodamine B solution. The compressive strength of the sintered porous scaffolds was up to 0.7 MPa with the porosity of 68–84%. Full article

(This article belongs to the Special Issue Bioceramics and Bioactive Glass-Based Materials)

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20 pages, 5113 KiB

Open AccessEditor’s ChoiceArticle

Surface Functionalization of Poly(l-lactide-co-glycolide) Membranes with RGD-Grafted Poly(2-oxazoline) for Periodontal Tissue Engineering

by Anna M. Tryba, Małgorzata Krok-Borkowicz, Michał Kula, Natalia Piergies, Mateusz Marzec, Erik Wegener, Justyna Frączyk, Rainer Jordan, Beata Kolesińska, Dieter Scharnweber, Czesława Paluszkiewicz and Elżbieta Pamuła

J. Funct. Biomater. 2022, 13(1), 4; https://doi.org/10.3390/jfb13010004 - 7 Jan 2022

Cited by 13 | Viewed by 4385

Abstract

Bone tissue defects resulting from periodontal disease are often treated using guided tissue regeneration (GTR). The barrier membranes utilized here should prevent soft tissue infiltration into the bony defect and simultaneously support bone regeneration. In this study, we designed a degradable poly(l [...] Read more.

Bone tissue defects resulting from periodontal disease are often treated using guided tissue regeneration (GTR). The barrier membranes utilized here should prevent soft tissue infiltration into the bony defect and simultaneously support bone regeneration. In this study, we designed a degradable poly(l-lactide-co-glycolide) (PLGA) membrane that was surface-modified with cell adhesive arginine-glycine-aspartic acid (RGD) motifs. For a novel method of membrane manufacture, the RGD motifs were coupled with the non-ionic amphiphilic polymer poly(2-oxazoline) (POx). The RGD-containing membranes were then prepared by solvent casting of PLGA, POx coupled with RGD (POx_RGD), and poly(ethylene glycol) (PEG) solution in methylene chloride (DCM), followed by DCM evaporation and PEG leaching. Successful coupling of RGD to POx was confirmed spectroscopically by Raman, Fourier transform infrared in attenuated reflection mode (FTIR-ATR), and X-ray photoelectron (XPS) spectroscopy, while successful immobilization of POx_RGD on the membrane surface was confirmed by XPS and FTIR-ATR. The resulting membranes had an asymmetric microstructure, as shown by scanning electron microscopy (SEM), where the glass-cured surface was more porous and had a higher surface area then the air-cured surface. The higher porosity should support bone tissue regeneration, while the air-cured side is more suited to preventing soft tissue infiltration. The behavior of osteoblast-like cells on PLGA membranes modified with POx_RGD was compared to cell behavior on PLGA foil, non-modified PLGA membranes, or PLGA membranes modified only with POx. For this, MG-63 cells were cultured for 4, 24, and 96 h on the membranes and analyzed by metabolic activity tests, live/dead staining, and fluorescent staining of actin fibers. The results showed bone cell adhesion, proliferation, and viability to be the highest on membranes modified with POx_RGD, making them possible candidates for GTR applications in periodontology and in bone tissue engineering. Full article

(This article belongs to the Special Issue Bioinspired Materials for Medical and Biotechnological Applications)

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20 pages, 1529 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Properties and Applications of PDMS for Biomedical Engineering: A Review

by Inês Miranda, Andrews Souza, Paulo Sousa, João Ribeiro, Elisabete M. S. Castanheira, Rui Lima and Graça Minas

J. Funct. Biomater. 2022, 13(1), 2; https://doi.org/10.3390/jfb13010002 - 21 Dec 2021

Cited by 459 | Viewed by 28248

Abstract

Polydimethylsiloxane (PDMS) is an elastomer with excellent optical, electrical and mechanical properties, which makes it well-suited for several engineering applications. Due to its biocompatibility, PDMS is widely used for biomedical purposes. This widespread use has also led to the massification of the soft-lithography [...] Read more.

Polydimethylsiloxane (PDMS) is an elastomer with excellent optical, electrical and mechanical properties, which makes it well-suited for several engineering applications. Due to its biocompatibility, PDMS is widely used for biomedical purposes. This widespread use has also led to the massification of the soft-lithography technique, introduced for facilitating the rapid prototyping of micro and nanostructures using elastomeric materials, most notably PDMS. This technique has allowed advances in microfluidic, electronic and biomedical fields. In this review, an overview of the properties of PDMS and some of its commonly used treatments, aiming at the suitability to those fields’ needs, are presented. Applications such as microchips in the biomedical field, replication of cardiovascular flow and medical implants are also reviewed. Full article

(This article belongs to the Special Issue Medical Application of Functional Biomaterials)

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12 pages, 2130 KiB

Open AccessEditor’s ChoiceArticle

Design of Asymmetric Nanofibers-Membranes Based on Polyvinyl Alcohol and Wool-Keratin for Wound Healing Applications

by Diego O. Sanchez Ramirez, Iriczalli Cruz-Maya, Claudia Vineis, Cinzia Tonetti, Alessio Varesano and Vincenzo Guarino

J. Funct. Biomater. 2021, 12(4), 76; https://doi.org/10.3390/jfb12040076 - 20 Dec 2021

Cited by 30 | Viewed by 4908

Abstract

The development of asymmetric membranes—i.e., matching two fibrous layers with selected composition and morphological properties to mimic both the epidermis and dermis—currently represents one of the most promising strategies to support skin regeneration during the wound healing process. Herein, a new asymmetric platform [...] Read more.

The development of asymmetric membranes—i.e., matching two fibrous layers with selected composition and morphological properties to mimic both the epidermis and dermis—currently represents one of the most promising strategies to support skin regeneration during the wound healing process. Herein, a new asymmetric platform fabricated by a sequential electrospinning process was investigated. The top layer comprises cross-linked polyvinylalcohol (PVA) nanofibers (NFs)—from water solution—to replicate the epidermis’s chemical stability and wettability features. Otherwise, the bottom layer is fabricated by integrating PVA with wool-keratin extracted via sulfitolysis. This protein is a biocompatibility polymer with excellent properties for dermis-like structures. Morphological characterization via SEM supported by image analysis showed that the asymmetric membrane exhibited average fiber size—max frequency diameter 450 nm, range 1.40 μm—and porosity suitable for the healing process. FTIR-spectrums confirmed the presence of keratin in the bottom layer and variations of keratin-secondary structures. Compared with pure PVA-NFs, keratin/PVA-NFs showed a significant improvement in cell adhesion in in vitro tests. In perspective, these asymmetric membranes could be promisingly used to confine active species (i.e., antioxidants, antimicrobials) to the bottom layer to support specific cell activities (i.e., proliferation, differentiation) in wound healing applications. Full article

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25 pages, 10331 KiB

Open AccessEditor’s ChoiceArticle

Functionalized Nanocellulose Drives Neural Stem Cells toward Neuronal Differentiation

by Sahitya Chetan Pandanaboina, Ambar B. RanguMagar, Krishna D. Sharma, Bijay P. Chhetri, Charlette M. Parnell, Jennifer Yanhua Xie, Malathi Srivatsan and Anindya Ghosh

J. Funct. Biomater. 2021, 12(4), 64; https://doi.org/10.3390/jfb12040064 - 22 Nov 2021

Cited by 6 | Viewed by 4287

Abstract

Transplantation of differentiated and fully functional neurons may be a better therapeutic option for the cure of neurodegenerative disorders and brain injuries than direct grafting of neural stem cells (NSCs) that are potentially tumorigenic. However, the differentiation of NSCs into a large population [...] Read more.

Transplantation of differentiated and fully functional neurons may be a better therapeutic option for the cure of neurodegenerative disorders and brain injuries than direct grafting of neural stem cells (NSCs) that are potentially tumorigenic. However, the differentiation of NSCs into a large population of neurons has been a challenge. Nanomaterials have been widely used as substrates to manipulate cell behavior due to their nano-size, excellent physicochemical properties, ease of synthesis, and versatility in surface functionalization. Nanomaterial-based scaffolds and synthetic polymers have been fabricated with topology resembling the micro-environment of the extracellular matrix. Nanocellulose materials are gaining attention because of their availability, biocompatibility, biodegradability and bioactivity, and affordable cost. We evaluated the role of nanocellulose with different linkage and surface features in promoting neuronal differentiation. Nanocellulose coupled with lysine molecules (CNC–Lys) provided positive charges that helped the cells to attach. Embryonic rat NSCs were differentiated on the CNC–Lys surface for up to three weeks. By the end of the three weeks of in vitro culture, 87% of the cells had attached to the CNC–Lys surface and more than half of the NSCs had differentiated into functional neurons, expressing endogenous glutamate, generating electrical activity and action potentials recorded by the multi-electrode array. Full article

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

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15 pages, 3221 KiB

Open AccessEditor’s ChoiceArticle

Preparation and Characterization of Moldable Demineralized Bone Matrix/Calcium Sulfate Composite Bone Graft Materials

by I-Cheng Chen, Chen-Ying Su, Chun-Cheih Lai, Yi-Syue Tsou, Yudong Zheng and Hsu-Wei Fang

J. Funct. Biomater. 2021, 12(4), 56; https://doi.org/10.3390/jfb12040056 - 4 Oct 2021

Cited by 24 | Viewed by 7712

Abstract

Demineralized bone matrix (DBM) is a decalcified allo/xenograft retaining collagen and noncollagenous proteins, which has been extensively used because of its osteoconductive and osteoinductive properties. Calcium sulfate (CaSO₄, CS) is a synthetic bone substitute used in bone healing with biocompatible, nontoxic, [...] Read more.

Demineralized bone matrix (DBM) is a decalcified allo/xenograft retaining collagen and noncollagenous proteins, which has been extensively used because of its osteoconductive and osteoinductive properties. Calcium sulfate (CaSO₄, CS) is a synthetic bone substitute used in bone healing with biocompatible, nontoxic, bioabsorbable, osteoconductive, and good mechanical characteristics. This study aims to prepare a DBM/CS composite bone graft material in a moldable putty form without compromising the peculiar properties of DBM and CS. For this purpose, firstly, porcine femur was defatted using chloroform/methanol and extracted by acid for demineralization, then freeze-dried and milled/sieved to obtain DBM powder. Secondly, the α-form and β-form of calcium sulfate hemihydrate (CaSO₄·0.5H₂O, CSH) were produced by heating gypsum (CaSO₄·2H₂O). The morphology and particle sizes of α- and β-CSH were obtained by SEM, and their chemical properties were confirmed by EDS, FTIR and XRD. Furthermore, the DBM-based graft was mixed with α- or β-CSH at a ratio of 9:1, and glycerol/4% HPMC was added as a carrier to produce a putty. DBM/CSH putty possesses a low washout rate, good mechanical strength and biocompatibility. In conclusion, we believe that the moldable DBM/CSH composite putty developed in this study could be a promising substitute for the currently available bone grafts, and might have practical application in the orthopedics field as a potential bone void filler. Full article

(This article belongs to the Special Issue Bioceramics and Bioactive Glass-Based Materials)

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12 pages, 3215 KiB

Open AccessEditor’s ChoiceArticle

In Vitro Corrosion of SiC-Coated Anodized Ti Nano-Tubular Surfaces

by Shu-Min Hsu, Chaker Fares, Xinyi Xia, Md Abu Jafar Rasel, Jacob Ketter, Samira Esteves Afonso Camargo, Md Amanul Haque, Fan Ren and Josephine F. Esquivel-Upshaw

J. Funct. Biomater. 2021, 12(3), 52; https://doi.org/10.3390/jfb12030052 - 16 Sep 2021

Cited by 8 | Viewed by 3900

Abstract

Peri-implantitis leads to implant failure and decreases long-term survival and success rates of implant-supported prostheses. The pathogenesis of this disease is complex but implant corrosion is believed to be one of the many factors which contributes to progression of this disease. A nanostructured [...] Read more.

Peri-implantitis leads to implant failure and decreases long-term survival and success rates of implant-supported prostheses. The pathogenesis of this disease is complex but implant corrosion is believed to be one of the many factors which contributes to progression of this disease. A nanostructured titanium dioxide layer was introduced using anodization to improve the functionality of dental implants. In the present study, we evaluated the corrosion performance of silicon carbide (SiC) on anodized titanium dioxide nanotubes (ATO) using plasma-enhanced chemical vapor deposition (PECVD). This was investigated through a potentiodynamic polarization test and bacterial incubation for 30 days. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze surface morphologies of non-coated and SiC-coated nanotubes. Energy dispersive X-ray (EDX) was used to analyze the surface composition. In conclusion, SiC-coated ATO exhibited improved corrosion resistance and holds promise as an implant coating material. Full article

(This article belongs to the Special Issue Nanoengineered Materials for Biomedical Applications)

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16 pages, 1176 KiB

Open AccessEditor’s ChoiceReview

Effect of Resin Infiltration on Enamel: A Systematic Review and Meta-Analysis

by Madalena Soveral, Vanessa Machado, João Botelho, José João Mendes and Cristina Manso

J. Funct. Biomater. 2021, 12(3), 48; https://doi.org/10.3390/jfb12030048 - 16 Aug 2021

Cited by 34 | Viewed by 7406

Abstract

Subsurface enamel demineralization beneath an intact surface layer or white spots lesions (WSL) can and should be treated with non-invasive procedures to impede the development of a cavitated lesion. We aim to analyze if infiltrative resin improves enamel roughness, microhardness, shear bond strength, [...] Read more.

Subsurface enamel demineralization beneath an intact surface layer or white spots lesions (WSL) can and should be treated with non-invasive procedures to impede the development of a cavitated lesion. We aim to analyze if infiltrative resin improves enamel roughness, microhardness, shear bond strength, and penetration depth. MEDLINE [via Pubmed], Cochrane Central Register of Controlled Trials, Embase, Web of Science, Scholar, and LILACS were searched until May 2021. Methodological quality was assessed using the Joanna Briggs Institute Clinical Appraisal Checklist for Experimental Studies. Pairwise ratio of means (ROM) meta-analyses were carried out to compare the enamel properties after treatment with infiltrative resin on sound enamel and WSLs. From a total of 1604 articles, 48 studies were included. Enamel surface roughness decreased 35% in sound enamel (95%CI: 0.49–0.85, I² = 98.2%) and 54% in WSLs (95%CI: 0.29–0.74, I² = 98.5%). Microhardness reduced 24% in sound enamel (95%CI: 0.73–0.80, I² = 99.1%) and increased by 68% in WSLs (95%CI: 1.51; 1.86, I² = 99.8%). Shear bond strength reduced of 25% in sound enamel (95%CI: 0.60; 0.95, I² = 96.9%) and increased by 89% in WSLs (95%CI: 1.28–2.79, I² = 99.8%). Penetration depth was 65.39% of the WSLs (95%CI: 56.11–74.66, I² = 100%). Infiltrative resins effectively promote evident changes in enamel properties in sound and WSLs. Future studies with long-term follow-ups are necessary to corroborate these results from experimental studies. Full article

(This article belongs to the Special Issue Recent Advances in Dental Implants and Biomaterials)

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