Journal of Functional Biomaterials

39 pages, 11595 KiB

Open AccessEditor’s ChoiceReview

Calcium Phosphate-Based Biomaterials for Bone Repair

by Xiaodong Hou, Lei Zhang, Zifei Zhou, Xiong Luo, Tianlong Wang, Xinyu Zhao, Bingqiang Lu, Feng Chen and Longpo Zheng

J. Funct. Biomater. 2022, 13(4), 187; https://doi.org/10.3390/jfb13040187 - 14 Oct 2022

Cited by 180 | Viewed by 13671

Abstract

Traumatic, tumoral, and infectious bone defects are common in clinics, and create a big burden on patient’s families and society. Calcium phosphate (CaP)-based biomaterials have superior properties and have been widely used for bone defect repair, due to their similarities to the inorganic [...] Read more.

Traumatic, tumoral, and infectious bone defects are common in clinics, and create a big burden on patient’s families and society. Calcium phosphate (CaP)-based biomaterials have superior properties and have been widely used for bone defect repair, due to their similarities to the inorganic components of human bones. The biological performance of CaPs, as a determining factor for their applications, are dependent on their physicochemical properties. Hydroxyapatite (HAP) as the most thermally stable crystalline phase of CaP is mostly used in the form of ceramics or composites scaffolds with polymers. Nanostructured CaPs with large surface areas are suitable for drug/gene delivery systems. Additionally, CaP scaffolds with hierarchical nano-/microstructures have demonstrated excellent ability in promoting bone regeneration. This review focuses on the relationships and interactions between the physicochemical/biological properties of CaP biomaterials and their species, sizes, and morphologies in bone regeneration, including synthesis strategies, structure control, biological behavior, and the mechanisms of CaP in promoting osteogenesis. This review will be helpful for scientists and engineers to further understand CaP-based biomaterials (CaPs), and be useful in developing new high-performance biomaterials for bone repair. Full article

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

► Show Figures

Figure 1

11 pages, 5324 KiB

Open AccessEditor’s ChoiceArticle

Effect of Surface Pre-Reacted Glass Ionomer Containing Dental Sealant on the Inhibition of Enamel Demineralization

by Yuko Ogawa, Mahmoud Sayed, Noriko Hiraishi, Nadin Al-Haj Husain, Junji Tagami, Mutlu Özcan and Yasushi Shimada

J. Funct. Biomater. 2022, 13(4), 189; https://doi.org/10.3390/jfb13040189 - 14 Oct 2022

Cited by 10 | Viewed by 3316

Abstract

The effect of a surface pre-reacted glass ionomer (S-PRG)-containing sealant on the demineralization inhibition and remineralization of intact enamel adjacent to the sealant material was investigated. BeautiSealant (BTS, S-PRG sealant, Shofu), Teeth Mate F-12.0 (TMF, fluoride-releasing sealant, Kuraray Noritake Dental), and an experimental [...] Read more.

The effect of a surface pre-reacted glass ionomer (S-PRG)-containing sealant on the demineralization inhibition and remineralization of intact enamel adjacent to the sealant material was investigated. BeautiSealant (BTS, S-PRG sealant, Shofu), Teeth Mate F-12.0 (TMF, fluoride-releasing sealant, Kuraray Noritake Dental), and an experimental silica-filler sealant were investigated. After pH cycling for 10 days, the enamel surface adjacent to the sealant material was observed using confocal laser microscopy and scanning electron microscopy. The polymerized sealant disks were immersed in a demineralized solution (pH: 4.3) to measure pH change. The enamel specimens with polymerized sealant disks were additionally immersed in demineralized solution, followed by energy-dispersive X-ray spectroscopy. The demineralized area of BTS was significantly smaller than that of TMF and SS (p < 0.05). The surfaces adjacent to the sealant of TMF and SS were demineralized, while the surface of BTS was comparatively intact. An increase in pH values were observed in the BTS and TMF groups. Enamel surfaces presented an inhibition of demineralization for BTS and TMF, but not for SS. Fluoride uptake from the polymerized sealant was greater for BTS than for TMF. The S-PRG-containing sealant showed a buffering ability, demineralization inhibition, promotion of remineralization, and it can be advised for clinical applications. Full article

(This article belongs to the Special Issue Functional Materials for Dental Restorations)

► Show Figures

Graphical abstract

16 pages, 3319 KiB

Open AccessEditor’s ChoiceArticle

Development of Ulvan-Containing Liposomes as Antibacterial Drug Delivery Platforms

by Leto-Aikaterini Tziveleka, Natassa Pippa, Efstathia Ioannou, Costas Demetzos and Vassilios Roussis

J. Funct. Biomater. 2022, 13(4), 186; https://doi.org/10.3390/jfb13040186 - 13 Oct 2022

Cited by 15 | Viewed by 3007

Abstract

Liposomes, due to their safety profile and targeting ability, are among the most studied nanocarriers as antimicrobial delivery systems. However, due to lack of stability and the non-specific interaction of liposomes with cells and proteins, their use is relatively limited. Aiming to overcome [...] Read more.

Liposomes, due to their safety profile and targeting ability, are among the most studied nanocarriers as antimicrobial delivery systems. However, due to lack of stability and the non-specific interaction of liposomes with cells and proteins, their use is relatively limited. Aiming to overcome these drawbacks, it was envisaged that incorporation of ulvan, a bioactive marine sulfated polysaccharide isolated from green algae, in liposomes could improve their physicochemical properties and overall stability. Thus, we initially studied the interactions of ulvan with neutral, negatively, and positively charged lipids using Differential Scanning Calorimetry and subsequently, based on the obtained results, we prepared the respective ulvan–containing neutral and charged liposomes, where ulvan interacts with both lipid chains and polar groups in the liposomal bilayer. In a further step, we entrapped in the liposomes fusidic acid, used as a model antibacterial drug, and proceeded with the evaluation of their antibacterial activity against Staphylococcus aureus. The physicochemical properties (size and ζ-potential), stability, morphology, and entrapment efficiency of the prepared liposomal formulations were determined. Full article

► Show Figures

Figure 1

23 pages, 8368 KiB

Open AccessEditor’s ChoiceArticle

Safe-by-Design Antibacterial Peroxide-Substituted Biomimetic Apatites: Proof of Concept in Tropical Dentistry

by Ika Dewi Ana, Any Lestari, Prescillia Lagarrigue, Jérémy Soulie, Rahmi Anggraeni, Françoise Maube-Bosc, Carole Thouron, Benjamin Duployer, Christophe Tenailleau and Christophe Drouet

J. Funct. Biomater. 2022, 13(3), 144; https://doi.org/10.3390/jfb13030144 - 7 Sep 2022

Cited by 15 | Viewed by 3225

Abstract

Bone infections are a key health challenge with dramatic consequences for affected patients. In dentistry, periodontitis is a medically compromised condition for efficient dental care and bone grafting, the success of which depends on whether the surgical site is infected or not. Present [...] Read more.

Bone infections are a key health challenge with dramatic consequences for affected patients. In dentistry, periodontitis is a medically compromised condition for efficient dental care and bone grafting, the success of which depends on whether the surgical site is infected or not. Present treatments involve antibiotics associated with massive bacterial resistance effects, urging for the development of alternative antibacterial strategies. In this work, we established a safe-by-design bone substitute approach by combining bone-like apatite to peroxide ions close to natural in vivo oxygenated species aimed at fighting pathogens. In parallel, bone-like apatites doped with Ag⁺ or co-doped Ag⁺/peroxide were also prepared for comparative purposes. The compounds were thoroughly characterized by chemical titrations, FTIR, XRD, SEM, and EDX analyses. All doped apatites demonstrated significant antibacterial properties toward four major pathogenic bacteria involved in periodontitis and bone infection, namely Porphyromonas gingivalis (P. gingivalis), Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Fusobacterium nucleatum (F. nucleatum), and S. aureus. By way of complementary tests to assess protein adsorption, osteoblast cell adhesion, viability and IC₅₀ values, the samples were also shown to be highly biocompatible. In particular, peroxidated apatite was the safest material tested, with the lowest IC₅₀ value toward osteoblast cells. We then demonstrated the possibility to associate such doped apatites with two biocompatible polymers, namely gelatin and poly(lactic-co-glycolic) acid PLGA, to prepare, respectively, composite 2D membranes and 3D scaffolds. The spatial distribution of the apatite particles and polymers was scrutinized by SEM and µCT analyses, and their relevance to the field of bone regeneration was underlined. Such bio-inspired antibacterial apatite compounds, whether pure or associated with (bio)polymers are thus promising candidates in dentistry and orthopedics while providing an alternative to antibiotherapy. Full article

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

► Show Figures

Graphical abstract

16 pages, 2273 KiB

Open AccessEditor’s ChoiceArticle

Effects of Different Titanium Surface Treatments on Adhesion, Proliferation and Differentiation of Bone Cells: An In Vitro Study

by Milan Stoilov, Lea Stoilov, Norbert Enkling, Helmut Stark, Jochen Winter, Michael Marder and Dominik Kraus

J. Funct. Biomater. 2022, 13(3), 143; https://doi.org/10.3390/jfb13030143 - 5 Sep 2022

Cited by 27 | Viewed by 3518

Abstract

The objective of this study was to evaluate the impacts of different sandblasting procedures in acid etching of Ti6Al4V surfaces on osteoblast cell behavior, regarding various physicochemical and topographical parameters. Furthermore, differences in osteoblast cell behavior between cpTi and Ti6Al4V SA surfaces were [...] Read more.

The objective of this study was to evaluate the impacts of different sandblasting procedures in acid etching of Ti6Al4V surfaces on osteoblast cell behavior, regarding various physicochemical and topographical parameters. Furthermore, differences in osteoblast cell behavior between cpTi and Ti6Al4V SA surfaces were evaluated. Sandblasting and subsequent acid etching of cpTi and Ti6Al4V discs was performed with Al₂O₃ grains of different sizes and with varying blasting pressures. The micro- and nano-roughness of the experimental SA surfaces were analyzed via confocal, atomic force and scanning electron microscopy. Surface free energy and friction coefficients were determined. hFOB 1.19 cells were seeded to evaluate adhesion, proliferation and osteoblastic differentiation for up to 12 d via crystal violet assays, MTT assays, ALP activity assays and Alizarin Red staining assays. Differences in blasting procedures had significant impacts on surface macro- and micro-topography. The crystal violet assay revealed a significant inverse relationship between blasting grain size and hFOB cell growth after 7 days. This trend was also visible in the Alizarin Red assays staining after 12 d: there was significantly higher biomineralization visible in the group that was sandblasted with smaller grains (F180) when compared to standard-grain-size groups (F70). SA samples treated with reduced blasting pressure exhibited lower hFOB adhesion and growth capabilities at initial (2 h) and later time points for up to 7 days, when compared to the standard SA surface, even though micro-roughness and other relevant surface parameters were similar. Overall, etched-only surfaces consistently exhibited equivalent or higher adhesion, proliferation and differentiation capabilities when compared to all other sandblasted and etched surfaces. No differences were found between cpTi and Ti6Al4V SA surfaces. Subtle modifications in the blasting protocol for Ti6Al4V SA surfaces significantly affect the proliferative and differentiation behavior of human osteoblasts. Surface roughness parameters are not sufficient to predict osteoblast behavior on etched Ti6Al4V surfaces. Full article

(This article belongs to the Special Issue Advanced Biomaterials and Oral Implantology)

► Show Figures

Figure 1

17 pages, 4154 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of the Antibacterial Properties of Iron Oxide, Polyethylene Glycol, and Gentamicin Conjugated Nanoparticles against Some Multidrug-Resistant Bacteria

by Farah M. Abdulsada, Nehia N. Hussein, Ghassan M. Sulaiman, Amer Al Ali and Muhanad Alhujaily

J. Funct. Biomater. 2022, 13(3), 138; https://doi.org/10.3390/jfb13030138 - 2 Sep 2022

Cited by 37 | Viewed by 4586

Abstract

Antibacterial resistance is observed as a public health issue around the world. Every day, new resistance mechanisms appear and spread over the world. For that reason, it is imperative to improve the treatment schemes that have been developed to treat infections caused by [...] Read more.

Antibacterial resistance is observed as a public health issue around the world. Every day, new resistance mechanisms appear and spread over the world. For that reason, it is imperative to improve the treatment schemes that have been developed to treat infections caused by wound infections, for instance, Staphylococcus epidermidis (S. epidermidis), Proteus mirabilis (P. mirabilis), and Acinetobacter baumannii (A. baumannii). In this case, we proposed a method that involves mixing the Gentamicin (Gen) with iron oxide nanoparticles (Fe₃O₄ NPs) and a polymer (polyethylene glycol (PEG)) with Fe₃O₄ NPs. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to characterize Fe₃O₄ NPs. Zeta potential and dynamic light scattering (DLS) were also assessed. The antibacterial activity of Fe₃O₄ NPs, Fe₃O₄ NPs+PEG, Fe₃O₄ NPs+Gen, and Fe₃O₄ NPs+PEG+Gen composites was investigated. The results showed a significant improvement in the antibacterial activity of nanoparticles against bacterial isolates, especially for the Fe₃O₄ NPs+PEG+Gen as the diameter of the inhibition zone reached 26.33 ± 0.57 mm for A. baumannii, 25.66 ± 0.57 mm for P. mirabilis, and 23.66 ± 0.57 mm for S. epidermidis. The Fe₃O₄ NPs, Fe₃O₄ NPs+PEG, Fe₃O₄+Gen, and Fe₃O₄+PEG+Gen also showed effectiveness against the biofilm produced by these isolated bacteria. The minimum inhibitory concentration (MIC) of Fe₃O₄ NPs for S. epidermidis was 25 µg mL⁻¹ and for P. mirabilis and A. baumannii was 50 µg mL⁻¹. The findings suggest that the prepared nanoparticles could be potential therapeutic options for treating wound infections caused by S. epidermidis, P. mirabilis, and A. baumannii. Full article

(This article belongs to the Special Issue Antibacterial, Antifungal Properties and Toxicity from Metallic Nanomaterials)

► Show Figures

Figure 1

43 pages, 4242 KiB

Open AccessEditor’s ChoiceReview

The Role of Optical Imaging in Translational Nanomedicine

by Evelien Hesemans, Kiana Buttiens, Bella B. Manshian and Stefaan J. Soenen

J. Funct. Biomater. 2022, 13(3), 137; https://doi.org/10.3390/jfb13030137 - 31 Aug 2022

Cited by 5 | Viewed by 3074

Abstract

Nanomedicines have been a major research focus in the past two decades and are increasingly emerging in a broad range of clinical applications. However, a proper understanding of their biodistribution is required to further progress the field of nanomedicine. For this, imaging methods [...] Read more.

Nanomedicines have been a major research focus in the past two decades and are increasingly emerging in a broad range of clinical applications. However, a proper understanding of their biodistribution is required to further progress the field of nanomedicine. For this, imaging methods to monitor the delivery and therapeutic efficacy of nanoparticles are urgently needed. At present, optical imaging is the most common method used to study the biodistribution of nanomaterials, where the unique properties of nanomaterials and advances in optical imaging can jointly result in novel methods for optimal monitoring of nanomaterials in preclinical animal models. This review article aims to give an introduction to nanomedicines and their translational impact to highlight the potential of optical imaging to study the biodistribution of nanoparticles and to monitor the delivery and therapeutic efficacy at the preclinical level. After introducing both domains, the review focuses on different techniques that can be used to overcome some intrinsic limitations of optical imaging and how this can specifically benefit nanoparticle studies. Finally, we point out some important key features of nanoparticles that currently hinder their full potential in the clinic and how the advances in optical imaging can help to provide us with the information needed to further boost the clinical translation and expand the field of nanomedicines. Full article

► Show Figures

Figure 1

12 pages, 5589 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Antimicrobial Fibrous Bandage-like Scaffolds Using Clove Bud Oil

by Carlota von Thadden, Esra Altun, Mehmet Aydogdu, Mohan Edirisinghe and Jubair Ahmed

J. Funct. Biomater. 2022, 13(3), 136; https://doi.org/10.3390/jfb13030136 - 30 Aug 2022

Cited by 3 | Viewed by 3979

Abstract

Wounds are characterised by an anatomical disruption of the skin; this leaves the body exposed to opportunistic pathogens which contribute to infections. Current wound healing bandages do little to protect against this and when they do, they can often utilise harmful additions. Historically, [...] Read more.

Wounds are characterised by an anatomical disruption of the skin; this leaves the body exposed to opportunistic pathogens which contribute to infections. Current wound healing bandages do little to protect against this and when they do, they can often utilise harmful additions. Historically, plant-based constituents have been extensively used for wound treatment and are proven beneficial in such environments. In this work, the essential oil of clove bud (Syzygium aromaticum) was incorporated in a polycaprolactone (PCL) solution, and 44.4% (v/v) oil-containing fibres were produced through pressurised gyration. The antimicrobial activity of these bandage-like fibres was analysed using in vitro disk diffusion and the physical fibre properties were also assessed. The work showed that advantageous fibre morphologies were achieved with diameters of 10.90 ± 4.99 μm. The clove bud oil fibres demonstrated good antimicrobial properties. They exhibited inhibition zone diameters of 30, 18, 11, and 20 mm against microbial colonies of C. albicans, E. coli, S. aureus, and S. pyogenes, respectively. These microbial species are commonly problematic in environments where the skin barrier is compromised. The outcomes of this study are thus very promising and suggest that clove bud oil is highly suitable to be applied as a natural sustainable alternative to modern medicine. Full article

(This article belongs to the Special Issue Biomaterials Sourced from Nature)

► Show Figures

Figure 1

14 pages, 3717 KiB

Open AccessEditor’s ChoiceArticle

The Effect of an Er, Cr: YSGG Laser Combined with Implantoplasty Treatment on Implant Surface Roughness and Morphologic Analysis: A Pilot In Vitro Study

by Chih-Jen Lin, Ming-Hsu Tsai, Yu-Ling Wu, Hsuan Lung, Hung-Shyong Chen and Aaron Yu-Jen Wu

J. Funct. Biomater. 2022, 13(3), 133; https://doi.org/10.3390/jfb13030133 - 29 Aug 2022

Cited by 2 | Viewed by 2394

Abstract

Although laser irradiation and implantoplasty (IP) are both treatment options for peri-implantitis, no studies have yet combined these two treatment solutions. The aim of this study was to identify the effect of an Er, Cr: YSGG laser on the IP surface. In experiment [...] Read more.

Although laser irradiation and implantoplasty (IP) are both treatment options for peri-implantitis, no studies have yet combined these two treatment solutions. The aim of this study was to identify the effect of an Er, Cr: YSGG laser on the IP surface. In experiment 1, TiUnite anodized surface implants were treated with an Er, Cr: YSGG laser at 0.5 to 2 W on the panel energy setting and 20 Hz under water irrigation. In experiment 2, all implant surfaces were treated with the IP procedure first, then irradiated with the Er, Cr: YSGG laser. All samples were analyzed by stereomicroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and surface topography. Stereomicroscopy and SEM revealed no obvious surface change at any energy setting once the surface was polished with the IP procedure, whereas damage was caused to the TiUnite original implant surface when the Er, Cr: YSGG laser panel energy was set at 1 W or higher. EDS showed no significant difference in element composition once the surface was polished with the IP procedure, while a compositional change was detected when the Er, Cr: YSGG laser panel energy was set to 0.5 W or higher to irradiate the original TiUnite surface. Surface roughness may be related to laser irradiation energy, but no significant changes occurred following IP. These results indicated that the Er, Cr: YSGG laser may have little effect on the post-IP surface compared with the virgin TiUnite surface. Full article

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

► Show Figures

Figure 1

14 pages, 2445 KiB

Open AccessEditor’s ChoiceArticle

Biological Activities of Glass Ionomer Cement Supplemented with Fortilin on Human Dental Pulp Stem Cells

by Prawichaya Sangsuwan, Sissada Tannukit, Wilaiwan Chotigeat and Ureporn Kedjarune-Leggat

J. Funct. Biomater. 2022, 13(3), 132; https://doi.org/10.3390/jfb13030132 - 28 Aug 2022

Cited by 7 | Viewed by 2321

Abstract

This study aimed to determine the most suitable recombinant fortilin and evaluate the biological activities of glass ionomer cement (GIC) incorporated with fortilin on human dental pulp stem cells (hDPSCs). Full-length and three fragments of Penaeus merguiensis fortilin were cloned and examined for [...] Read more.

This study aimed to determine the most suitable recombinant fortilin and evaluate the biological activities of glass ionomer cement (GIC) incorporated with fortilin on human dental pulp stem cells (hDPSCs). Full-length and three fragments of Penaeus merguiensis fortilin were cloned and examined for their proliferative and cytoprotective effects on hDPSCs by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Human DPSCs were cultured with GIC supplemented with fortilin, tricalcium phosphate, or a combination of tricalcium phosphate and fortilin, designated as GIC + FL, GIC + TCP, and GIC + TCP + FL, respectively (n = 4 for each group). At given time points, hDPSCs were harvested and analyzed by MTT, quantitative reverse transcription polymerase chain reaction, alkaline phosphatase activity, and Alizarin Red assays. The full-length fortilin promoted cell proliferation and significantly increased cell survival. This protein was subsequently added into the GIC along with tricalcium phosphate to investigate the biological activities. All experimental groups showed reduced cell viability after treatment with modified GICs on days 1 and 3. The GIC + TCP + FL group significantly promoted odontoblastic differentiation at particular time points. In addition, alkaline phosphatase activity and calcium phosphate deposit were markedly increased in the GIC + TCP + FL group. Among all experimental groups, the GIC incorporated with fortilin and tricalcium phosphate demonstrated the best results on odontogenic differentiation and mineral deposition in hDPSCs. Full article

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

► Show Figures

Figure 1

10 pages, 3085 KiB

Open AccessEditor’s ChoiceArticle

Polyelectrolyte Multilayers Composed of Polyethyleneimine-Grafted Chitosan and Polyacrylic Acid for Controlled-Drug-Delivery Applications

by Eliz Selmin Paker and Mehmet Senel

J. Funct. Biomater. 2022, 13(3), 131; https://doi.org/10.3390/jfb13030131 - 28 Aug 2022

Cited by 10 | Viewed by 2600

Abstract

In this work, polyethyleneimine (PEI)-grafted chitosan (Chi-g-PEI) was prepared for the fabrication of layer-by-layer (LBL) films for use in sustained-drug-delivery applications. Chi-g-PEI and polyacrylic acid (PAA) multilayer films were formed using the LBL technique. Methylene blue (MB) was used as a model drug [...] Read more.

In this work, polyethyleneimine (PEI)-grafted chitosan (Chi-g-PEI) was prepared for the fabrication of layer-by-layer (LBL) films for use in sustained-drug-delivery applications. Chi-g-PEI and polyacrylic acid (PAA) multilayer films were formed using the LBL technique. Methylene blue (MB) was used as a model drug for the investigation of loading and release capabilities of the LBL films. Characterizations of the synthesized copolymer were performed using Fourier-transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (NMR), Thermogravimetric analysis (TGA), and X-ray Powder Diffraction (XRD) techniques, and the thickness of the LBL films was measured using Atomic force microscopy (AFM). The drug-loading and -release behaviors of the LBL films were assessed using a UV–visible spectrophotometer. The results showed that the loading capacity and release rate of MB were affected by ionic strength and pH. In addition, it was demonstrated that PEI-grafted chitosan is a good candidate for the assembling of LBL films for drug-delivery applications. Full article

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

► Show Figures

Figure 1

14 pages, 4804 KiB

Open AccessEditor’s ChoiceArticle

Bioactive Silicon Nitride Implant Surfaces with Maintained Antibacterial Properties

by Ioannis Katsaros, Yijun Zhou, Ken Welch, Wei Xia, Cecilia Persson and Håkan Engqvist

J. Funct. Biomater. 2022, 13(3), 129; https://doi.org/10.3390/jfb13030129 - 27 Aug 2022

Cited by 8 | Viewed by 3496

Abstract

Silicon nitride (Si₃N₄) is a promising biomaterial, currently used in spinal fusion implants. Such implants should result in high vertebral union rates without major complications. However, pseudarthrosis remains an important complication that could lead to a need for implant [...] Read more.

Silicon nitride (Si₃N₄) is a promising biomaterial, currently used in spinal fusion implants. Such implants should result in high vertebral union rates without major complications. However, pseudarthrosis remains an important complication that could lead to a need for implant replacement. Making silicon nitride implants more bioactive could lead to higher fusion rates, and reduce the incidence of pseudarthrosis. In this study, it was hypothesized that creating a highly negatively charged Si₃N₄ surface would enhance its bioactivity without affecting the antibacterial nature of the material. To this end, samples were thermally, chemically, and thermochemically treated. Apatite formation was examined for a 21-day immersion period as an in-vitro estimate of bioactivity. Staphylococcus aureus bacteria were inoculated on the surface of the samples, and their viability was investigated. It was found that the thermochemically and chemically treated samples exhibited enhanced bioactivity, as demonstrated by the increased spontaneous formation of apatite on their surface. All modified samples showed a reduction in the bacterial population; however, no statistically significant differences were noticed between groups. This study successfully demonstrated a simple method to improve the in vitro bioactivity of Si₃N₄ implants while maintaining the bacteriostatic properties. Full article

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

► Show Figures

Figure 1

12 pages, 1608 KiB

Open AccessEditor’s ChoiceArticle

Improve Dentin Bonding Performance Using a Hydrolytically Stable, Ether-Based Primer

by Xiaohong Wang, Shinobu Yamauchi and Jirun Sun

J. Funct. Biomater. 2022, 13(3), 128; https://doi.org/10.3390/jfb13030128 - 26 Aug 2022

Cited by 3 | Viewed by 3823

Abstract

The objective of this study is to replace a traditional methacrylate-based primer (glycine, N-(2-hydroxy-3-(2-methyl-1-oxo-2-propenyl)propyl)-N-(4-methylphenyl) monosodium salt, NTG-GMA) with a hydrolytically stable ether-based primer (glycine, N-2-hydroxy-3-(4-vinylbenzyloxy)-propyl-N-(4-methylphenyl), monosodium salt, NTG-VBGE). The performance and durability of bonding composites to detin of two primers combined with methacrylate-based [...] Read more.

The objective of this study is to replace a traditional methacrylate-based primer (glycine, N-(2-hydroxy-3-(2-methyl-1-oxo-2-propenyl)propyl)-N-(4-methylphenyl) monosodium salt, NTG-GMA) with a hydrolytically stable ether-based primer (glycine, N-2-hydroxy-3-(4-vinylbenzyloxy)-propyl-N-(4-methylphenyl), monosodium salt, NTG-VBGE). The performance and durability of bonding composites to detin of two primers combined with methacrylate-based or ether-based adhesives were evaluated using shear bond strength (SBS) and micro-tensile bond strength (μTBS) combined with thermal cycling. The hydrolysis resistance of NTG-VBGE against hydrolysis was tested by challenging primed hydroxyapatite crystals with an esterase. The hydrophilicity of the primers and the resin spreading kinetics of adhesives on primed dentin were characterized by water contact angle measurements. The new primer NTG-VBGE was found to be compatible with both methacrylate-based adhesives and ether-based adhesives. The highest μTBS values were found in the test group of NTG-VBGE and ether-based adhesive, which was consistent with the resin spreading kinetics results. The more hydrophobic and hydrolytically stable primer/adhesive achieved improved dentin infiltration and bonding strength, suggesting significant potential for further developing dental restorative materials with extended service life. Full article

(This article belongs to the Section Dental Biomaterials)

► Show Figures

Figure 1

20 pages, 1672 KiB

Open AccessEditor’s ChoiceReview

Biopolymer Nanoparticles for Nose-to-Brain Drug Delivery: A New Promising Approach for the Treatment of Neurological Diseases

by Nicolò Montegiove, Eleonora Calzoni, Carla Emiliani and Alessio Cesaretti

J. Funct. Biomater. 2022, 13(3), 125; https://doi.org/10.3390/jfb13030125 - 24 Aug 2022

Cited by 42 | Viewed by 6010

Abstract

Diseases affecting the central nervous system (CNS) are among the most disabling and the most difficult to cure due to the presence of the blood–brain barrier (BBB) which represents an impediment from a therapeutic and diagnostic point of view as it limits the [...] Read more.

Diseases affecting the central nervous system (CNS) are among the most disabling and the most difficult to cure due to the presence of the blood–brain barrier (BBB) which represents an impediment from a therapeutic and diagnostic point of view as it limits the entry of most drugs. The use of biocompatible polymer nanoparticles (NPs) as vehicles for targeted drug delivery to the brain arouses increasing interest. However, the route of administration of these vectors remains critical as the drug must be delivered without being degraded to achieve a therapeutic effect. An innovative approach for the administration of drugs to the brain using polymeric carriers is represented by the nose-to-brain (NtB) route which involves the administration of the therapeutic molecule through the neuro-olfactory epithelium of the nasal mucosa. Nasal administration is a non-invasive approach that allows the rapid transport of the drug directly to the brain and minimizes its systemic exposure. To date, many studies involve the use of polymer NPs for the NtB transport of drugs to the brain for the treatment of a whole series of disabling neurological diseases for which, as of today, there is no cure. In this review, various types of biodegradable polymer NPs for drug delivery to the brain through the NtB route are discussed and particular attention is devoted to the treatment of neurological diseases such as Glioblastoma and neurodegenerative diseases. Full article

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

► Show Figures

Figure 1

18 pages, 3431 KiB

Open AccessEditor’s ChoiceReview

The Roles of Exosomes upon Metallic Ions Stimulation in Bone Regeneration

by Xuwei Luo, Dongqin Xiao, Chengdong Zhang and Guanglin Wang

J. Funct. Biomater. 2022, 13(3), 126; https://doi.org/10.3390/jfb13030126 - 24 Aug 2022

Cited by 14 | Viewed by 3119

Abstract

Metallic ions have been widely investigated and incorporated into bone substitutes for bone regeneration owing to their superior capacity to induce angiogenesis and osteogenesis. Exosomes are key paracrine mediators that play a crucial role in cell-to-cell communication. However, the role of exosomes in [...] Read more.

Metallic ions have been widely investigated and incorporated into bone substitutes for bone regeneration owing to their superior capacity to induce angiogenesis and osteogenesis. Exosomes are key paracrine mediators that play a crucial role in cell-to-cell communication. However, the role of exosomes in metallic ion-induced bone formation and their underlying mechanisms remain unclear. Thus, this review systematically analyzes the effects of metallic ions and metallic ion-incorporated biomaterials on exosome secretion from mesenchymal stem cells (MSCs) and macrophages, as well as the effects of secreted exosomes on inflammation, angiogenesis, and osteogenesis. In addition, possible signaling pathways involved in metallic ion-mediated exosomes, followed by bone regeneration, are discussed. Despite limited investigation, metallic ions have been confirmed to regulate exosome production and function, affecting immune response, angiogenesis, and osteogenesis. Although the underlying mechanism is not yet clear, these insights enrich our understanding of the mechanisms of the metallic ion-induced microenvironment for bone regeneration, benefiting the design of metallic ion-incorporated implants. Full article

► Show Figures

Figure 1

14 pages, 4310 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of a New Porcine Bone Graft on the Repair of Surgically Created Critical Bone Defects in Rat Calvaria: Histomorphometric and Microtomographic Study

by Ytalo Fernandes, Rafael Mantovani, Danilo Reino, Arthur Novaes, Jr., Michel Messora, Luiz Gustavo Sousa, Daniela Palioto and Sergio Scombatti de Souza

J. Funct. Biomater. 2022, 13(3), 124; https://doi.org/10.3390/jfb13030124 - 23 Aug 2022

Cited by 7 | Viewed by 2227

Abstract

The aim of this study was to evaluate the use of a new porcine bone graft in rat calvaria bone defects. Critical defects were surgically created in 24 rats that were divided into four experimental groups according to defect filling (n = [...] Read more.

The aim of this study was to evaluate the use of a new porcine bone graft in rat calvaria bone defects. Critical defects were surgically created in 24 rats that were divided into four experimental groups according to defect filling (n = 6): Control Group (CG)—blood clot; Porcine Bone Group (PG)—porcine-derived bone substitute; (BG): Bio-Oss Group (BG)–chemically and heat-treated bovine graft; Bonefill Group (BFG)—chemically treated bovine bone substitute. Euthanasia of the animals occurred 30 days after the surgery, and the area of the original surgical defect and the surrounding tissues were removed for micro-CT and histomorphometric analysis. In the micro-CT evaluation, the PG presented statistically significant differences (p < 0.05) in comparison to the CG, BG and BFG, for the parameters percentage of Bone Volume (BV/TV), Surface Bone Density (BS/TV), Number of Trabeculae (Tb.N) and Bone Connectivity (Conn), but not for Total Porosity (Po.tot) and Trabecular Thickness (Tb.Th). The histomorphometric analysis showed that the PG presented similar results to the BG regarding newly formed bone extension and to the BG and BFG regarding newly formed bone area. The porcine-derived graft presented superior microtomographic and histomorphometric results when compared to the two bovine bone substitutes. Full article

► Show Figures

Figure 1

14 pages, 2692 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Bone Response to a Nano HA Implant Surface on Sinus Lifting Procedures: Study in Rabbits

by Sergio H. L. Martins, Uislen B. Cadore, Arthur B. Novaes, Jr., Michel R. Messora, Bruna Ghiraldini, Fabio J. B. Bezerra, Daniele Botticelli and Sergio L. S. de Souza

J. Funct. Biomater. 2022, 13(3), 122; https://doi.org/10.3390/jfb13030122 - 21 Aug 2022

Cited by 3 | Viewed by 2290

Abstract

The aim of this study was to evaluate the bone response to two different implant surfaces on sinus lift procedures in rabbits. Bilateral sinus lifting with inorganic bovine bone associated with collagen membrane and immediate implantation were performed in 16 rabbits. Custom mini-implants [...] Read more.

The aim of this study was to evaluate the bone response to two different implant surfaces on sinus lift procedures in rabbits. Bilateral sinus lifting with inorganic bovine bone associated with collagen membrane and immediate implantation were performed in 16 rabbits. Custom mini-implants were randomly installed in the prepared sites: one side received a double acid-etched (DAE) surface and the other a nano-hydroxyapatite (NHA) surface. The animals were euthanized 30 and 60 days after surgery, and biopsies were collected for microtomographic and histomorphometric analysis. After 30 days, no intra- and inter-group statistical differences were observed in microtomographic analysis, while at 60 days, bone analysis showed statistically significant differences between groups (p < 0.05) for all the evaluated parameters. Histomorphometric analysis showed, after 30 days, mean % of Bone-to-Implant Contact (BIC) for DAE and NHA of 31.70 ± 10.42% vs. 40.60 ± 10.22% (p > 0.05), respectively; for % of Bone Area Fraction Occupancy (BAFO), mean values were 45.43 ± 3.597% for DAE and 57.04 ± 5.537% for NHA (p < 0.05). After 60 days, mean %BIC and %BAFO for DAE and NHA implants were statistically significant (p < 0.05). The NHA surface showed superior biological features compared to the DAE treatment, promoting higher bone formation around the implants in an experimental model of bone repair in a grafted area. Full article

(This article belongs to the Special Issue How Biomaterials and Implants Influence the Healing after Maxillary Sinus Floor Elevation)

► Show Figures

Figure 1

16 pages, 3708 KiB

Open AccessEditor’s ChoiceArticle

Application of Injectable, Crosslinked, Fibrin-Containing Hyaluronic Acid Scaffolds for In Vivo Remodeling

by Adél Hinsenkamp, Ágnes Fülöp, László Hricisák, Éva Pál, Kiara Kun, Aliz Majer, Viktória Varga, Zsombor Lacza and István Hornyák

J. Funct. Biomater. 2022, 13(3), 119; https://doi.org/10.3390/jfb13030119 - 13 Aug 2022

Cited by 10 | Viewed by 2703

Abstract

The present research aimed to characterize soft tissue implants that were prepared with the use of crosslinked hyaluronic acid (HA) using two different crosslinkers and multiple reagent concentrations, alone or in combination with fibrin. The effect of the implants was evaluated in an [...] Read more.

The present research aimed to characterize soft tissue implants that were prepared with the use of crosslinked hyaluronic acid (HA) using two different crosslinkers and multiple reagent concentrations, alone or in combination with fibrin. The effect of the implants was evaluated in an in vivo mouse model, after 4 weeks in one group and after 12 weeks in the other. The explants were compared using analytical methods, evaluating microscopic images, and a histology analysis. The kinetics of the degradation and remodeling of explants were found to be greatly dependent on the concentration and type of crosslinker; generally, divinyl sulfone (DVS) resists degradation more effectively compared to butanediol diglycidyl ether (BDDE). The presence of fibrin enhances the formation of blood vessels, and the infiltration of cells and extracellular matrix. In summary, if the aim is to create a soft tissue implant with easier degradation of the HA content, then the use of 2–5% BDDE is found to be optimal. For a longer degradation time, 5% DVS is the more suitable crosslinker. The use of fibrin was found to support the biological process of remodeling, while keeping the advances of HA in void filling, enabling the parallel degradation and remodeling processes. Full article

► Show Figures

Figure 1

29 pages, 2185 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Three-Dimensional Bioprinting for Cartilage Tissue Engineering: Insights into Naturally-Derived Bioinks from Land and Marine Sources

by Marta Anna Szychlinska, Fabio Bucchieri, Alberto Fucarino, Alfredo Ronca and Ugo D’Amora

J. Funct. Biomater. 2022, 13(3), 118; https://doi.org/10.3390/jfb13030118 - 12 Aug 2022

Cited by 34 | Viewed by 6295

Abstract

In regenerative medicine and tissue engineering, the possibility to: (I) customize the shape and size of scaffolds, (II) develop highly mimicked tissues with a precise digital control, (III) manufacture complex structures and (IV) reduce the wastes related to the production process, are the [...] Read more.

In regenerative medicine and tissue engineering, the possibility to: (I) customize the shape and size of scaffolds, (II) develop highly mimicked tissues with a precise digital control, (III) manufacture complex structures and (IV) reduce the wastes related to the production process, are the main advantages of additive manufacturing technologies such as three-dimensional (3D) bioprinting. Specifically, this technique, which uses suitable hydrogel-based bioinks, enriched with cells and/or growth factors, has received significant consideration, especially in cartilage tissue engineering (CTE). In this field of interest, it may allow mimicking the complex native zonal hyaline cartilage organization by further enhancing its biological cues. However, there are still some limitations that need to be overcome before 3D bioprinting may be globally used for scaffolds’ development and their clinical translation. One of them is represented by the poor availability of appropriate, biocompatible and eco-friendly biomaterials, which should present a series of specific requirements to be used and transformed into a proper bioink for CTE. In this scenario, considering that, nowadays, the environmental decline is of the highest concerns worldwide, exploring naturally-derived hydrogels has attracted outstanding attention throughout the scientific community. For this reason, a comprehensive review of the naturally-derived hydrogels, commonly employed as bioinks in CTE, was carried out. In particular, the current state of art regarding eco-friendly and natural bioinks’ development for CTE was explored. Overall, this paper gives an overview of 3D bioprinting for CTE to guide future research towards the development of more reliable, customized, eco-friendly and innovative strategies for this field of interest. Full article

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

► Show Figures

Figure 1

31 pages, 8068 KiB

Open AccessEditor’s ChoiceReview

Alginate-Based Bio-Composites and Their Potential Applications

by Khmais Zdiri, Aurélie Cayla, Adel Elamri, Annaëlle Erard and Fabien Salaun

J. Funct. Biomater. 2022, 13(3), 117; https://doi.org/10.3390/jfb13030117 - 10 Aug 2022

Cited by 44 | Viewed by 7522

Abstract

Over the last two decades, bio-polymer fibers have attracted attention for their uses in gene therapy, tissue engineering, wound-healing, and controlled drug delivery. The most commonly used bio-polymers are bio-sourced synthetic polymers such as poly (glycolic acid), poly (lactic acid), poly (e-caprolactone), copolymers [...] Read more.

Over the last two decades, bio-polymer fibers have attracted attention for their uses in gene therapy, tissue engineering, wound-healing, and controlled drug delivery. The most commonly used bio-polymers are bio-sourced synthetic polymers such as poly (glycolic acid), poly (lactic acid), poly (e-caprolactone), copolymers of polyglycolide and poly (3-hydroxybutyrate), and natural polymers such as chitosan, soy protein, and alginate. Among all of the bio-polymer fibers, alginate is endowed with its ease of sol–gel transformation, remarkable ion exchange properties, and acid stability. Blending alginate fibers with a wide range of other materials has certainly opened many new opportunities for applications. This paper presents an overview on the modification of alginate fibers with nano-particles, adhesive peptides, and natural or synthetic polymers, in order to enhance their properties. The application of alginate fibers in several areas such as cosmetics, sensors, drug delivery, tissue engineering, and water treatment are investigated. The first section is a brief theoretical background regarding the definition, the source, and the structure of alginate. The second part deals with the physico-chemical, structural, and biological properties of alginate bio-polymers. The third part presents the spinning techniques and the effects of the process and solution parameters on the thermo-mechanical and physico-chemical properties of alginate fibers. Then, the fourth part presents the additives used as fillers in order to improve the properties of alginate fibers. Finally, the last section covers the practical applications of alginate composite fibers. Full article

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

► Show Figures

Figure 1

19 pages, 1255 KiB

Open AccessEditor’s ChoiceReview

Application of Biocompatible Drug Delivery Nanosystems for the Treatment of Naturally Occurring Cancer in Dogs

by Nicola Ambrosio, Silvia Voci, Agnese Gagliardi, Ernesto Palma, Massimo Fresta and Donato Cosco

J. Funct. Biomater. 2022, 13(3), 116; https://doi.org/10.3390/jfb13030116 - 7 Aug 2022

Cited by 9 | Viewed by 3862

Abstract

Background: Cancer is a common disease in dogs, with a growing incidence related to the age of the animal. Nanotechnology is being employed in the veterinary field in the same manner as in human therapy. Aim: This review focuses on the application of [...] Read more.

Background: Cancer is a common disease in dogs, with a growing incidence related to the age of the animal. Nanotechnology is being employed in the veterinary field in the same manner as in human therapy. Aim: This review focuses on the application of biocompatible nanocarriers for the treatment of canine cancer, paying attention to the experimental studies performed on dogs with spontaneously occurring cancer. Methods: The most important experimental investigations based on the use of lipid and non-lipid nanosystems proposed for the treatment of canine cancer, such as liposomes and polymeric nanoparticles containing doxorubicin, paclitaxel and cisplatin, are described and their in vivo fate and antitumor features discussed. Conclusions: Dogs affected by spontaneous cancers are useful models for evaluating the efficacy of drug delivery systems containing antitumor compounds. Full article

(This article belongs to the Special Issue Selected Reviews in Biomaterials: Development, Applications and Challenges)

► Show Figures

Graphical abstract

13 pages, 12519 KiB

Open AccessEditor’s ChoiceArticle

Dentin Sealing of Calcium Silicate-Based Sealers in Root Canal Retreatment: A Confocal Laser Microscopy Study

by Blanca Ortiz-Blanco, José Luis Sanz, Carmen Llena, Adrián Lozano and Leopoldo Forner

J. Funct. Biomater. 2022, 13(3), 114; https://doi.org/10.3390/jfb13030114 - 4 Aug 2022

Cited by 5 | Viewed by 3471

Abstract

The aim of the present in vitro study was to evaluate the intratubular penetration of three bioceramic sealers in root canal retreatment. Here, 30 single-rooted human teeth were instrumented with the Protaper Universal system and filled with gutta-percha and the epoxy-resin-based sealer AH [...] Read more.

The aim of the present in vitro study was to evaluate the intratubular penetration of three bioceramic sealers in root canal retreatment. Here, 30 single-rooted human teeth were instrumented with the Protaper Universal system and filled with gutta-percha and the epoxy-resin-based sealer AH Plus mixed with rhodamine B. After two weeks in a humid environment, they were re-instrumented with Reciproc Blue and divided into three groups according to the endodontic sealer to be used in the re-filling (n = 10): G1: CeraSeal, G2: TotalFill BC Sealer, G3: TotalFill BC Sealer HiFlow. For the filling, a single cone technique was used, and the respective sealers were mixed with fluorescein. The roots were then sectioned at 2, 5, and 8 mm (apical, medial, and coronal measurement points, respectively) from the apex, and the dentinal tubule penetration depth and percentage of penetration around the canal perimeter were evaluated by means of confocal laser scanning microscopy (CLSM). Penetration between groups was compared using the Kruskal−Wallis test, and within each group using the Wilcoxon test. Statistical significance was established at p < 0.05. A non-significant reduction was found in the penetration depths and in a percentage of penetration around the canal perimeter between AH Plus and the tested calcium-silicate-based sealers (p > 0.05). Consequently, this reduction may not affect the three-dimensional seal of the root canal system in a negative manner. The penetration depth and percentage of penetration around the canal perimeter at both the root canal treatment and retreatment were significantly reduced from the coronal to apical points in all groups (p < 0.05). Full article

(This article belongs to the Special Issue Endodontic Biomaterials)

► Show Figures

Figure 1

24 pages, 9029 KiB

Open AccessEditor’s ChoiceArticle

Trilateral Multi-Functional Polyamide 12 Nanocomposites with Binary Inclusions for Medical Grade Material Extrusion 3D Printing: The Effect of Titanium Nitride in Mechanical Reinforcement and Copper/Cuprous Oxide as Antibacterial Agents

by Nectarios Vidakis, Markos Petousis, Nikolaos Mountakis, Apostolos Korlos, Vassilis Papadakis and Amalia Moutsopoulou

J. Funct. Biomater. 2022, 13(3), 115; https://doi.org/10.3390/jfb13030115 - 4 Aug 2022

Cited by 29 | Viewed by 3417

Abstract

In this work, for the first time, polyamide 12 (PA12) nanocomposites with binary inclusions in material extrusion (MEX) 3D printing were developed. The aim was to achieve an enhanced mechanical response with the addition of titanium nitride (TiN) and antibacterial performance with the [...] Read more.

In this work, for the first time, polyamide 12 (PA12) nanocomposites with binary inclusions in material extrusion (MEX) 3D printing were developed. The aim was to achieve an enhanced mechanical response with the addition of titanium nitride (TiN) and antibacterial performance with the addition of copper (Cu) or cuprous oxide (Cu₂O), towards the development of multi-functional nanocomposite materials, exploiting the 3D printing process benefits. The prepared nanocomposites were fully characterized for their mechanical properties. The thermal properties were also investigated. Morphological characterization was performed with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The antibacterial performance was investigated with an agar-well diffusion screening process. Overall, the introduction of these nanofillers induced antibacterial performance in the PA12 matrix materials, while at the same time, the mechanical performance was significantly increased. The results of the study show high potential for expanding the areas in which 3D printing can be used. Full article

► Show Figures

Figure 1

10 pages, 5377 KiB

Open AccessEditor’s ChoiceArticle

PLGA Nanoparticles Uptake in Stem Cells from Human Exfoliated Deciduous Teeth and Oral Keratinocyte Stem Cells

by Maria Tizu, Ion Mărunțelu, Bogdan Mihai Cristea, Claudiu Nistor, Nikolay Ishkitiev, Zornitsa Mihaylova, Rozaliya Tsikandelova, Marina Miteva, Ana Caruntu, Cristina Sabliov, Bogdan Calenic and Ileana Constantinescu

J. Funct. Biomater. 2022, 13(3), 109; https://doi.org/10.3390/jfb13030109 - 31 Jul 2022

Cited by 25 | Viewed by 2901

Abstract

Polymeric nanoparticles have been introduced as a delivery vehicle for active compounds in a broad range of medical applications due to their biocompatibility, stability, controlled release of active compounds, and reduced toxicity. The oral route is the most used approach for delivery of [...] Read more.

Polymeric nanoparticles have been introduced as a delivery vehicle for active compounds in a broad range of medical applications due to their biocompatibility, stability, controlled release of active compounds, and reduced toxicity. The oral route is the most used approach for delivery of biologics to the body. The homeostasis and function of oral cavity tissues are dependent on the activity of stem cells. The present work focuses, for the first time, on the interaction between two types of polymeric nanoparticles, poly (lactic-co-glycolic acid) or PLGA and PLGA/chitosan, and two stem cell populations, oral keratinocyte stem cells (OKSCs) and stem cells from human exfoliated deciduous teeth (SHEDs). The main results show that statistical significance was observed in OKSCs uptake when compared with normal keratinocytes and transit amplifying cells after 24 h of incubation with 5 and 10 µg/mL PLGA/chitosan. The CD117⁺ SHED subpopulation incorporated more PLGA/chitosan nanoparticles than nonseparated SHED. The uptake for PLGA/chitosan particles was better than for PLGA particles with longer incubation times, yielding better results in both cell types. The present results demonstrate that nanoparticle uptake depends on stem cell type, incubation time, particle concentration, and surface properties. Full article

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

► Show Figures

Figure 1

15 pages, 15461 KiB

Open AccessEditor’s ChoiceArticle

In Vivo Evaluation of the Effects of B-Doped Strontium Apatite Nanoparticles Produced by Hydrothermal Method on Bone Repair

by Faruk Oztekin, Turan Gurgenc, Serkan Dundar, Ibrahim Hanifi Ozercan, Tuba Talo Yildirim, Mehmet Eskibaglar, Erhan Cahit Ozcan and Cevher Kursat Macit

J. Funct. Biomater. 2022, 13(3), 110; https://doi.org/10.3390/jfb13030110 - 31 Jul 2022

Cited by 6 | Viewed by 3948

Abstract

In the present study, the structural, morphological, and in vivo biocompatibility of un-doped and boron (B)-doped strontium apatite (SrAp) nanoparticles were investigated. Biomaterials were fabricated using the hydrothermal process. The structural and morphological characterizations of the fabricated nanoparticles were performed by XRD, FT-IR, [...] Read more.

In the present study, the structural, morphological, and in vivo biocompatibility of un-doped and boron (B)-doped strontium apatite (SrAp) nanoparticles were investigated. Biomaterials were fabricated using the hydrothermal process. The structural and morphological characterizations of the fabricated nanoparticles were performed by XRD, FT-IR, FE-SEM, and EDX. Their biocompatibility was investigated by placing them in defects in rat tibiae in vivo. The un-doped and B-doped SrAp nanoparticles were successfully fabricated. The produced nanoparticles were in the shape of nano-rods, and the dimensions of the nano-rods decreased as the B ratio increased. It was observed that the structural and morphological properties of strontium apatite nanoparticles were affected by the contribution of B. A stoichiometric Sr/P ratio of 1.67 was reached in the 5% B-doped sample (1.68). The average crystallite sizes were 34.94 nm, 39.70 nm, 44.93 nm, and 48.23 nm in un-doped, 1% B-doped, 5% B-doped, and 10% B-doped samples, respectively. The results of the in vivo experiment revealed that the new bone formation and osteoblast density were higher in the groups with SrAp nanoparticles doped with different concentrations of B than in the control group, in which the open defects were untreated. It was observed that this biocompatibility and the new bone formation were especially elevated in the B groups, which added high levels of strontium were added. The osteoblast density was higher in the group in which the strontium element was placed in the opened bone defect compared with the control group. However, although new bone formation was slightly higher in the strontium group than in the control group, the difference was not statistically significant. Furthermore, the strontium group had the highest amount of fibrotic tissue formation. The produced nanoparticles can be used in dental and orthopedic applications as biomaterials. Full article

(This article belongs to the Special Issue Frontiers in Biodegradable Materials and Their Processing)

► Show Figures

Figure 1

18 pages, 3510 KiB

Open AccessEditor’s ChoiceArticle

Anti-Inflammatory and Mineralization Effects of an ASP/PLGA-ASP/ACP/PLLA-PLGA Composite Membrane as a Dental Pulp Capping Agent

by Wenjuan Yan, Fenghe Yang, Zhongning Liu, Quan Wen, Yike Gao, Xufeng Niu and Yuming Zhao

J. Funct. Biomater. 2022, 13(3), 106; https://doi.org/10.3390/jfb13030106 - 29 Jul 2022

Cited by 11 | Viewed by 3534

Abstract

Dental pulp is essential for the development and long-term preservation of teeth. Dental trauma and caries often lead to pulp inflammation. Vital pulp therapy using dental pulp-capping materials is an approach to preserving the vitality of injured dental pulp. Most pulp-capping materials used [...] Read more.

Dental pulp is essential for the development and long-term preservation of teeth. Dental trauma and caries often lead to pulp inflammation. Vital pulp therapy using dental pulp-capping materials is an approach to preserving the vitality of injured dental pulp. Most pulp-capping materials used in clinics have good biocompatibility to promote mineralization, but their anti-inflammatory effect is weak. Therefore, the failure rate will increase when dental pulp inflammation is severe. The present study developed an amorphous calcium phosphate/poly (L-lactic acid)-poly (lactic-co-glycolic acid) membrane compounded with aspirin (hereafter known as ASP/PLGA-ASP/ACP/PLLA-PLGA). The composite membrane, used as a pulp-capping material, effectively achieved the rapid release of high concentrations of the anti-inflammatory drug aspirin during the early stages as well as the long-term release of low concentrations of aspirin and calcium/phosphorus ions during the later stages, which could repair inflamed dental pulp and promote mineralization. Meanwhile, the composite membrane promoted the proliferation of inflamed dental pulp stem cells, downregulated the expression of inflammatory markers, upregulated the expression of mineralization-related markers, and induced the formation of stronger reparative dentin in the rat pulpitis model. These findings indicate that this material may be suitable for use as a pulp-capping material in clinical applications. Full article

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

► Show Figures

Figure 1

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 2993

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)

► Show Figures

Graphical abstract

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 7 | Viewed by 2966

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)

► Show Figures

Figure 1

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 24 | Viewed by 4460

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)

► Show Figures

Figure 1

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 6 | Viewed by 2952

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)

► Show Figures

Figure 1

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 3741

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)

► Show Figures

Figure 1

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 6 | Viewed by 3945

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)

► Show Figures

Figure 1

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 2751

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)

► Show Figures

Figure 1

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 34 | Viewed by 5231

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)

► Show Figures

Figure 1

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 3482

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)

► Show Figures

Figure 1

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 8 | Viewed by 3515

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)

► Show Figures

Figure 1

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 134 | Viewed by 13235

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)

► Show Figures

Figure 1

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 16 | Viewed by 4431

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)

► Show Figures

Graphical abstract

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 9 | Viewed by 3538

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)

► Show Figures

Figure 1

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 50 | Viewed by 7122

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)

► Show Figures

Graphical abstract

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 3832

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)

► Show Figures

Figure 1

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 3556

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)

► Show Figures

Graphical abstract

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 15 | Viewed by 4288

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)

► Show Figures

Figure 1

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 29 | Viewed by 5409

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)

► Show Figures

Figure 1

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 9 | Viewed by 4440

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)

► Show Figures

Graphical abstract

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 5 | Viewed by 3419

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)

► Show Figures

Graphical abstract

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 19 | Viewed by 3713

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)

► Show Figures

Graphical abstract

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 20 | Viewed by 3084

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

► Show Figures

Figure 1

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 130 | Viewed by 12493

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

► Show Figures

Figure 1

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 5690

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)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Editor’s Choice Articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI