Open AccessArticle
The Effects of Uniquely-Processed Titanium on Balance and Walking Performance in Healthy Older Adults
J. Funct. Biomater. 2018, 9(2), 39; https://doi.org/10.3390/jfb9020039 -
Abstract
The increased risk of falls associated with advancing age has increased demand for methods to improve balance and mobility. The primary purpose of the study was to determine whether wearing Aqua Titan-treated stockings could improve balance and walking performance in an older population;
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The increased risk of falls associated with advancing age has increased demand for methods to improve balance and mobility. The primary purpose of the study was to determine whether wearing Aqua Titan-treated stockings could improve balance and walking performance in an older population; secondary was to elucidate the mechanisms. In a randomized, double-blind crossover, 16 healthy older adults (age, 67.9 ± 4.2 years; BMI, 24.8 ± 3.1 kg/m2) performed two 4-day trials composed of baseline measures and fatiguing exercise on Day 1, with recovery measures at 14, 38 and 62 h post-exercise, wearing Aqua Titan and control stockings. Balance, walking performance, triceps surae stretch reflex, ankle range of motion and gastrocnemius muscle microvascular perfusion, blood flow and oxygen consumption were measured at baseline and during recovery. Aqua Titan had no effect on the microvascular parameters, but increased total ankle range of motion at 38 h (2.4°; 95% CI ± 1.8°) and 62 h (2.7°; ±1.7°), contributed to by increases in dorsiflexion and plantar flexion. There was decreasing persistence in the medial-lateral center of pressure movement at 38 h (q = 0, −0.0635 ± 0.0455), compared to control stockings. Aqua Titan garments hold potential for improving balance and mobility in older adults in the days following a bout of fatiguing exercise. The proposed mechanisms associated with enhanced sensory feedback require further exploration. Full article
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Open AccessRetraction
Retraction: Azuma, K. et al. Chitin, Chitosan, and Its Derivatives for Wound Healing: Old and New Materials. J. Funct. Biomater. 2015, 6, 104–142
J. Funct. Biomater. 2018, 9(2), 38; https://doi.org/10.3390/jfb9020038 -
Abstract
The Journal of Functional Biomaterials Editorial Office have been made aware that some parts of the article [1] are duplicated from other publications[...] Full article
Open AccessArticle
Mechanical Behavior Optimization of Chitosan Extracted from Shrimp Shells as a Sustainable Material for Shopping Bags
J. Funct. Biomater. 2018, 9(2), 37; https://doi.org/10.3390/jfb9020037 -
Abstract
The use of biodegradable materials for shopping bag production, and other products made from plastics, has recently been an object of intense research—with the aim of reducing the environmental burdens given by conventional materials. Chitosan is a potential material because of its biocompatibility,
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The use of biodegradable materials for shopping bag production, and other products made from plastics, has recently been an object of intense research—with the aim of reducing the environmental burdens given by conventional materials. Chitosan is a potential material because of its biocompatibility, degradability, and non-toxicity. It is a semi-natural biopolymeric material produced by the deacetylation of chitin, which is the second most abundant natural biopolymer (after cellulose). Chitin is found in the exoskeleton of insects, marine crustaceans, and the cell walls of certain fungi and algae. The raw materials most abundantly available are the shells of crab, shrimp, and prawn. Hence, in this study chitosan was selected as one of the main components of biodegradable materials used for shopping bag production. Firstly, chitin was extracted from shrimp shell waste and then converted to chitosan. The chitosan was next ground to a powder. Although, currently, polyethylene bags are prepared by blown extrusion, in this preliminary research the chitosan powder was dissolved in a solvent and the films were cast. Composite films with several fillers were used as a reinforcement at different dosages to optimize mechanical properties, which have been assessed using tensile tests. These results were compared with those of conventional polyethylene bags used in Egypt. Overall, the chitosan films were found to have a lower ductility but appeared to be strong enough to fulfill shopping bag functions. The addition of fillers, such as chitin whiskers and rice straw, enhanced the mechanical properties of chitosan films, while the addition of chitin worsened overall mechanical behavior. Full article
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Open AccessFeature PaperArticle
Encapsulation and Characterization of Gentamicin Sulfate in the Collagen Added Electrospun Nanofibers for Skin Regeneration
J. Funct. Biomater. 2018, 9(2), 36; https://doi.org/10.3390/jfb9020036 -
Abstract
In the current practice, the clinical use of conventional skin substitutes such as autogenous skin grafts have shown several problems, mainly with respect to limited sources and donor site morbidity. In order to overcome these limitations, the use of smart synthetic biomaterials is
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In the current practice, the clinical use of conventional skin substitutes such as autogenous skin grafts have shown several problems, mainly with respect to limited sources and donor site morbidity. In order to overcome these limitations, the use of smart synthetic biomaterials is tremendously diffusing as skin substitutes. Indeed, engineered skin grafts or analogues frequently play an important role in the treatment of chronic skin wounds, by supporting the regeneration of newly formed tissue, and at the same time preventing infections during the long-term treatment. In this context, natural proteins such as collagen—natively present in the skin tissue—embedded in synthetic polymers (i.e., PCL) allow the development of micro-structured matrices able to mimic the functions and to structure of the surrounding extracellular matrix. Moreover, the encapsulation of drugs, such as gentamicin sulfate, also improves the bioactivity of nanofibers, due to the efficient loading and a controlled drug release towards the site of interest. Herein, we have done a preliminary investigation on the capability of gentamicin sulfate, loaded into collagen-added nanofibers, for the controlled release in local infection treatments. Experimental studies have demonstrated that collagen added fibers can be efficaciously used to administrate gentamicin for 72 h without any toxic in vitro response, thus emerging as a valid candidate for the therapeutic treatment of infected wounds. Full article
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Open AccessCommunication
Carbon Dots Doped with Dysprosium: A Bimodal Nanoprobe for MRI and Fluorescence Imaging
J. Funct. Biomater. 2018, 9(2), 35; https://doi.org/10.3390/jfb9020035 -
Abstract
In recent years, functional nanoprobes with multiple imaging modalities have become an emerging field of biomedical research. In this preliminary study, we utilized a facile hydrothermal method for the preparation of magneto-fluorescent bimodal carbon dots doped with dysprosium (Dy-CDs). The prepared Dy-CDs have
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In recent years, functional nanoprobes with multiple imaging modalities have become an emerging field of biomedical research. In this preliminary study, we utilized a facile hydrothermal method for the preparation of magneto-fluorescent bimodal carbon dots doped with dysprosium (Dy-CDs). The prepared Dy-CDs have shown a good colloidal stability in a water solution and strong blue–green fluorescence, with a maximum at 452 nm. In addition, the excellent transverse relaxivity of the prepared Dy-CDs (r2 = 7.42 ± 0.07 mM−1s−1) makes them also suitable for T2-weighted magnetic resonance imaging (MRI). Thus, synthesized Dy-CDs could be potentially utilized for both MRI and fluorescence imaging of living cells. Full article
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Open AccessReview
Honey, Wound Repair and Regenerative Medicine
J. Funct. Biomater. 2018, 9(2), 34; https://doi.org/10.3390/jfb9020034 -
Abstract
Honey possesses anti-bacterial, anti-inflammatory and other properties that are useful for wound healing and tissue regeneration. Furthermore, honey has been used for millennia in folk medicine. The misuse of antibiotics has again boosted the use of honey in regenerative medicine. The multifaceted properties
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Honey possesses anti-bacterial, anti-inflammatory and other properties that are useful for wound healing and tissue regeneration. Furthermore, honey has been used for millennia in folk medicine. The misuse of antibiotics has again boosted the use of honey in regenerative medicine. The multifaceted properties of honey could possibly be exploited for scaffold applications in tissue healing. Full article
Open AccessArticle
Synthesis and Characterization of Injectable Hydrogels with Varying Collagen–Chitosan–Thymosin β4 Composition for Myocardial Infarction Therapy
J. Funct. Biomater. 2018, 9(2), 33; https://doi.org/10.3390/jfb9020033 -
Abstract
Thirty percent of global mortalities are caused by cardiovascular disease, and 54% of the aforementioned amount is instigated by ischemic heart disease that triggered myocardial infarction. Myocardial infarction is due to blood flow cessation in certain coronary arteries that causes lack of oxygen
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Thirty percent of global mortalities are caused by cardiovascular disease, and 54% of the aforementioned amount is instigated by ischemic heart disease that triggered myocardial infarction. Myocardial infarction is due to blood flow cessation in certain coronary arteries that causes lack of oxygen (ischemia) and stimulates myocardial necrosis. One of the methods to treat myocardial infarction consists in injecting cells or active biomolecules and biomaterials into heart infarction locations. This study aimed to investigate the characteristics of a collagen–chitosan-based hydrogel with variations in its chitosan composition. The prepared hydrogels contained thymosin β4 (Tβ4), a 43-amino acid peptide with angiogenic and cardioprotective properties which can act as a bioactive molecule for the treatment of myocardial infarction. A morphological structure analysis showed that the hydrogels lacked interconnecting pores. All samples were not toxic on the basis of a cytotoxicity test. A histopathological anatomy test showed that the collagen–chitosan–thymosin β4 hydrogels could stimulate angiogenesis and epicardial heart cell migration, as demonstrated by the evaluation of the number of blood vessels and the infiltration extent of myofibroblasts. Full article
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Open AccessArticle
Poly-L-lactic Acid (PLLA)-Chitosan-Collagen Electrospun Tube for Vascular Graft Application
J. Funct. Biomater. 2018, 9(2), 32; https://doi.org/10.3390/jfb9020032 -
Abstract
Poly-L-Lactic acid (PLLA) blended with chitosan and collagen was used to fabricate a conduit for blood vessel engineering through an electrospinning process. Various concentrations of chitosan were used in the blend in order to study its effect on the morphology, chemical bond, tensile
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Poly-L-Lactic acid (PLLA) blended with chitosan and collagen was used to fabricate a conduit for blood vessel engineering through an electrospinning process. Various concentrations of chitosan were used in the blend in order to study its effect on the morphology, chemical bond, tensile strength, burst pressure, hemocompatibility, and cell viability (cytotoxicity) of the tube.In vitro assessments indicated that addition of chitosan-collagen could improve cell viability and hemocompatibility. Best results were demonstrated by the conduit with 10% PLLA, 0.5% chitosan, and 1% collagen. Tensile strength reached 2.13 MPa and burst pressure reached 2593 mmHg, both values that are within the range value of native blood vessel. A hemolysis percentage of 1.04% and a cell viability of 86.2% were obtained, meeting the standards of high hemocompatibility and low cytotoxicity for vascular graft material. The results are promising for further development toward vascular graft application. Full article
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Open AccessReview
Nail Properties and Bone Health: A Review
J. Funct. Biomater. 2018, 9(2), 31; https://doi.org/10.3390/jfb9020031 -
Abstract
Physicochemical properties of nail may offer valuable insight into the health of bone. Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard technique for evaluating bone health through bone mineral density (BMD). However, only 70% of fractures are explained by low BMD according
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Physicochemical properties of nail may offer valuable insight into the health of bone. Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard technique for evaluating bone health through bone mineral density (BMD). However, only 70% of fractures are explained by low BMD according to DXA. Therefore, the World Health Organisation recommended the need for the development of alternative methods of assessing bone health. Keratin and collagen type I are major proteins in nail and bone, respectively. Both of these proteins undergo post-translational modifications, with a possible correlation between the degree of post-translational modifications in keratin and collagen. Raman spectroscopy is a technique used to detect changes in protein composition and structure. As changes in protein function and structure may be associated with the development of osteoporosis, Raman spectroscopy may be a valuable adjunct to assess bone health and fracture risk. This review critically evaluates various methods and techniques to identify the link between nail properties and bone health. The strengths and limitations of various studies and the potential use of nail protein and minerals to evaluate bone health have been also presented. Full article
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Open AccessArticle
Growing Neural PC-12 Cell on Crosslinked Silica Aerogels Increases Neurite Extension in the Presence of an Electric Field
J. Funct. Biomater. 2018, 9(2), 30; https://doi.org/10.3390/jfb9020030 -
Abstract
Externally applied electrical stimulation (ES) has been shown to enhance the nerve regeneration process and to influence the directionality of neurite outgrowth. In addition, the physical and chemical properties of the substrate used for nerve-cell regeneration is critical in fostering regeneration. Previously, we
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Externally applied electrical stimulation (ES) has been shown to enhance the nerve regeneration process and to influence the directionality of neurite outgrowth. In addition, the physical and chemical properties of the substrate used for nerve-cell regeneration is critical in fostering regeneration. Previously, we have shown that polyurea-crosslinked silica aerogels (PCSA) exert a positive influence on the extension of neurites by PC-12 cells, a cell-line model widely used to study neurite extension and electrical excitability. In this work, we have examined how an externally applied electric field (EF) influences the extension of neurites in PC-12 cells grown on two substrates: collagen-coated dishes versus collagen-coated crosslinked silica aerogels. The externally applied direct current (DC) bias was applied in vitro using a custom-designed chamber containing polydimethysiloxane (PDMS) embedded copper electrodes to create an electric field across the substrate for the cultured PC-12 cells. Results suggest orientation preference towards the anode, and, on average, longer neurites in the presence of the applied DC bias than with 0 V DC bias. In addition, neurite length was increased in cells grown on silica-crosslinked aerogel when compared to cells grown on regular petri-dishes. These results further support the notion that PCSA is a promising material for nerve regeneration. Full article
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Open AccessArticle
Novel Chlorhexidine-Loaded Polymeric Nanoparticles for Root Canal Treatment
J. Funct. Biomater. 2018, 9(2), 29; https://doi.org/10.3390/jfb9020029 -
Abstract
Persistence of microorganisms in dentinal tubules after root canal chemo-mechanical preparation has been well documented. The complex anatomy of the root canal and dentinal buffering ability make delivery of antimicrobial agents difficult. This work explores the use of a novel trilayered nanoparticle (TNP)
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Persistence of microorganisms in dentinal tubules after root canal chemo-mechanical preparation has been well documented. The complex anatomy of the root canal and dentinal buffering ability make delivery of antimicrobial agents difficult. This work explores the use of a novel trilayered nanoparticle (TNP) drug delivery system that encapsulates chlorhexidine digluconate, which is aimed at improving the disinfection of the root canal system. Chlorhexidine digluconate was encapsulated inside polymeric self-assembled TNPs. These were self-assembled through water-in-oil emulsion from poly(ethylene glycol)-b-poly(lactic acid) (PEG-b-PLA), a di-block copolymer, with one hydrophilic segment and another hydrophobic. The resulting TNPs were physicochemically characterized and their antimicrobial effectiveness was evaluated against Enterococcus faecalis using a broth inhibition method. The hydrophilic interior of the TNPs successfully entrapped chlorhexidine digluconate. The resulting TNPs had particle size ranging from 140–295 nm, with adequate encapsulation efficiency, and maintained inhibition of bacteria over 21 days. The delivery of antibacterial irrigants throughout the dentinal matrix by employing the TNP system described in this work may be an effective alternative to improve root canal disinfection. Full article
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Open AccessArticle
Rapidly-Dissolving Silver-Containing Bioactive Glasses for Cariostatic Applications
J. Funct. Biomater. 2018, 9(2), 28; https://doi.org/10.3390/jfb9020028 -
Abstract
A novel bioactive glass series containing incremental amounts of silver oxide was synthesized, ground down, and subsequently incorporated into a dentifrice for the purpose of reducing the incidence of dental caries and lesion formation. Three glasses were synthesized using the melt quench route:
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A novel bioactive glass series containing incremental amounts of silver oxide was synthesized, ground down, and subsequently incorporated into a dentifrice for the purpose of reducing the incidence of dental caries and lesion formation. Three glasses were synthesized using the melt quench route: Si-Control (70SiO2–12CaO–3P2O5–15Na2O, mol %), Si-02 and Si-05, where 0.2 and 0.5 mol % Ag2O were substituted, respectively, for SiO2 in Si-Control. The glasses were then ground, sieved, characterized, and dissolved in Tris buffer solution (pH = 7.30) for 6, 12, and 24 h, with the pH of the resultant solution being recorded and the ions that were released into solution quantified. Samples of each glass were subsequently embedded into a non-fluoridated, commercially available toothpaste which was then used to brush resin-mounted lamb molars which, up to the point of testing, had been stored in a 1.0 M HCl solution. Knoop microhardness measurements of the molars were recorded before and after brushing to determine the presence of remineralization on the surface of the teeth (surface hardness loss of 37%, 35%, and 34% for Si-Control, Si-02 and Si-05, respectively, after 24 h). Four oral cavity bacterial strains were isolated through swabs of the inner cheek, gums, and teeth surfaces of three volunteers, and placed on agar discs. Of each glass, 0.5 g was placed onto the discs, and the resultant inhibition zones were measured after 6, 12, and 24 h. Si-05 performed better than Si-02 on two strains after 24 h, while exhibiting similar behavior for the remaining two strains after 24 h; the largest inhibition zone measured was 2.8 mm, for Si-05 after 12 h. Si-Control exhibited no antibacterial effect at any time point, providing evidence for the role of silver oxide as the antibacterial component of these glasses. Full article
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Open AccessFeature PaperArticle
Short-Term Degradation of Bi-Component Electrospun Fibers: Qualitative and Quantitative Evaluations via AFM Analysis
J. Funct. Biomater. 2018, 9(2), 27; https://doi.org/10.3390/jfb9020027 -
Abstract
Electrospun polymeric fibers are currently used as 3D models for in vitro applications in biomedical areas, i.e., tissue engineering, cell and drug delivery. The high customization of the electrospinning process offers numerous opportunities to manipulate and control surface area, fiber diameter, and fiber
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Electrospun polymeric fibers are currently used as 3D models for in vitro applications in biomedical areas, i.e., tissue engineering, cell and drug delivery. The high customization of the electrospinning process offers numerous opportunities to manipulate and control surface area, fiber diameter, and fiber density to evaluate the response of cells under different morphological and/or biochemical stimuli. The aim of this study was to investigate—via atomic force microscopy (AFM)—the chemical and morphological changes in bi-component electrospun fibers (BEFs) during the in vitro degradation process using a biological medium. BEFs were fabricated by electrospinning a mixture of synthetic-polycaprolactone (PCL)-and natural polymers (gelatin) into a binary solution. During the hydrolytic degradation of protein, no significant remarkable effects were recognized in terms of fiber integrity. However, increases in surface roughness as well as a decrease in fiber diameter as a function of the degradation conditions were detected. We suggest that morphological and chemical changes due to the local release of gelatin positively influence cell behavior in culture, in terms of cell adhesion and spreading, thus working to mimic the native microenvironment of natural tissues. Full article
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Open AccessCorrection
Correction: W.C. Mak, et al. Controlled Delivery of Human Cells by Temperature Responsive Microcapsules. J. Funct. Biomater. 2015, 6, 439–453
J. Funct. Biomater. 2018, 9(2), 26; https://doi.org/10.3390/jfb9020026 -
Abstract
Recently, we found a mistake in Figure 4D in our previously published paper[...] Full article
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Open AccessReview
Bioactive Glasses: Where Are We and Where Are We Going?
J. Funct. Biomater. 2018, 9(1), 25; https://doi.org/10.3390/jfb9010025 -
Abstract
Bioactive glasses caused a revolution in healthcare and paved the way for modern biomaterial-driven regenerative medicine. The first 45S5 glass composition, invented by Larry Hench fifty years ago, was able to bond to living bone and to stimulate osteogenesis through the release of
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Bioactive glasses caused a revolution in healthcare and paved the way for modern biomaterial-driven regenerative medicine. The first 45S5 glass composition, invented by Larry Hench fifty years ago, was able to bond to living bone and to stimulate osteogenesis through the release of biologically-active ions. 45S5-based glass products have been successfully implanted in millions of patients worldwide, mainly to repair bone and dental defects and, over the years, many other bioactive glass compositions have been proposed for innovative biomedical applications, such as soft tissue repair and drug delivery. The full potential of bioactive glasses seems still yet to be fulfilled, and many of today’s achievements were unthinkable when research began. As a result, the research involving bioactive glasses is highly stimulating and requires a cross-disciplinary collaboration among glass chemists, bioengineers, and clinicians. The present article provides a picture of the current clinical applications of bioactive glasses, and depicts six relevant challenges deserving to be tackled in the near future. We hope that this work can be useful to both early-stage researchers, who are moving with their first steps in the world of bioactive glasses, and experienced scientists, to stimulate discussion about future research and discover new applications for glass in medicine. Full article
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Open AccessFeature PaperReview
Bioactive Glasses: From Parent 45S5 Composition to Scaffold-Assisted Tissue-Healing Therapies
J. Funct. Biomater. 2018, 9(1), 24; https://doi.org/10.3390/jfb9010024 -
Abstract
Nowadays, bioactive glasses (BGs) are mainly used to improve and support the healing process of osseous defects deriving from traumatic events, tumor removal, congenital pathologies, implant revisions, or infections. In the past, several approaches have been proposed in the replacement of extensive bone
[...] Read more.
Nowadays, bioactive glasses (BGs) are mainly used to improve and support the healing process of osseous defects deriving from traumatic events, tumor removal, congenital pathologies, implant revisions, or infections. In the past, several approaches have been proposed in the replacement of extensive bone defects, each one with its own advantages and drawbacks. As a result, the need for synthetic bone grafts is still a remarkable clinical challenge since more than 1 million bone-graft surgical operations are annually performed worldwide. Moreover, recent studies show the effectiveness of BGs in the regeneration of soft tissues, too. Often, surgical criteria do not match the engineering ones and, thus, a compromise is required for getting closer to an ideal outcome in terms of good regeneration, mechanical support, and biocompatibility in contact with living tissues. The aim of the present review is providing a general overview of BGs, with particular reference to their use in clinics over the last decades and the latest synthesis/processing methods. Recent advances in the use of BGs in tissue engineering are outlined, where the use of porous scaffolds is gaining growing importance thanks to the new possibilities given by technological progress extended to both manufacturing processes and functionalization techniques. Full article
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Open AccessFeature PaperArticle
First Results of a New Vacuum Plasma Sprayed (VPS) Titanium-Coated Carbon/PEEK Composite Cage for Lumbar Interbody Fusion
J. Funct. Biomater. 2018, 9(1), 23; https://doi.org/10.3390/jfb9010023 -
Abstract
The aim of this study was to assess the performance of a new vacuum plasma sprayed (VPS) titanium-coated carbon/polyetheretherketone (PEEK) cage under first use clinical conditions. Forty-two patients who underwent a one or two segment transforaminal lumbar interbody fusion (TLIF) procedure with a
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The aim of this study was to assess the performance of a new vacuum plasma sprayed (VPS) titanium-coated carbon/polyetheretherketone (PEEK) cage under first use clinical conditions. Forty-two patients who underwent a one or two segment transforaminal lumbar interbody fusion (TLIF) procedure with a new Ca/PEEK composite cage between 2012 and 2016 were retrospectively identified by an electronic patient chart review. Fusion rates (using X-ray), patient’s satisfaction, and complications were followed up for two years. A total of 90.4% of the patients were pain-free and satisfied after a follow up (FU) period of 29.1 ± 9 (range 24–39) months. A mean increase of 3° in segmental lordosis in the early period (p = 0.002) returned to preoperative levels at final follow-ups. According to the Bridwell classification, the mean 24-month G1 fusion rate was calculated as 93.6% and the G2 as 6.4%. No radiolucency around the cage (G3) or clear pseudarthrosis could be seen (G4). In conclusion, biological properties of the inert, hydrophobic surface, which is the main disadvantage of PEEK, can be improved with VPS titanium coating, so that the carbon/PEEK composite cage, which has great advantages in respect of biomechanical properties, can be used safely in TLIF surgery. High fusion rates, good clinical outcome, and low implant-related complication rates without the need to use rhBMP or additional iliac bone graft can be achieved. Full article
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Open AccessFeature PaperReview
Recent Advances in Biomaterials for 3D Printing and Tissue Engineering
J. Funct. Biomater. 2018, 9(1), 22; https://doi.org/10.3390/jfb9010022 -
Abstract
Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology.
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Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology. Many researchers have developed novel biomaterials and compositions to enable their use in 3D printing methods. The advantages of fabricating scaffolds using 3D printing are numerous, including the ability to create complex geometries, porosities, co-culture of multiple cells, and incorporate growth factors. In this review, recently-developed biomaterials for different tissues are discussed. Biomaterials used in 3D printing are categorized into ceramics, polymers, and composites. Due to the nature of 3D printing methods, most of the ceramics are combined with polymers to enhance their printability. Polymer-based biomaterials are 3D printed mostly using extrusion-based printing and have a broader range of applications in regenerative medicine. The goal of tissue engineering is to fabricate functional and viable organs and, to achieve this, multiple biomaterials and fabrication methods need to be researched. Full article
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Open AccessArticle
Electron Beam Immobilization of Novel Antimicrobial, Short Peptide Motifs Leads to Membrane Surfaces with Promising Antibacterial Properties
J. Funct. Biomater. 2018, 9(1), 21; https://doi.org/10.3390/jfb9010021 -
Abstract
In this study, the efficacy of electron beam irradiation versus chemical coupling for yielding polyethersulfone (PES) membranes with antibacterial properties was investigated. For the surface coating, a recently discovered lead compound, IL-KKA, comprising a short peptide sequence functionalized with imidazolium groups, was used.
[...] Read more.
In this study, the efficacy of electron beam irradiation versus chemical coupling for yielding polyethersulfone (PES) membranes with antibacterial properties was investigated. For the surface coating, a recently discovered lead compound, IL-KKA, comprising a short peptide sequence functionalized with imidazolium groups, was used. For better integration within the membrane, several novel variants of IL-KKA were generated. Membrane immobilization was achieved using different doses of electron beam irradiation and NHS/EDC chemical coupling. Physicochemical characterization of the coated membranes was performed by water contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy. Our results show that electron beam irradiation is as effective and gentle as chemical coupling using the NHS/EDC method. Moreover, it was demonstrated that the obtained membranes exhibit promising antibacterial activity against B. subtilis. In summary, the technique presented herein might be promising as a template for developing future anti-biofilm devices. Full article
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Open AccessFeature PaperArticle
Antimicrobial Monomers for Polymeric Dental Restoratives: Cytotoxicity and Physicochemical Properties
J. Funct. Biomater. 2018, 9(1), 20; https://doi.org/10.3390/jfb9010020 -
Abstract
A trend for the next generation of polymeric dental restoratives is to incorporate multifunctional capabilities to regulate microbial growth and remineralize tooth surfaces. Polymerizable 2-(methacryloyloxy)-N-(2-(methacryloyloxy)ethyl)-N,N-dimethylethan-1-aminium bromide (IDMA1) and N,N′-([1,1′-biphenyl]-2,2′-diylbis(methylene))bis(2-(methacryloyloxy)-N,N-dimethylethan-1-aminium) bromide
[...] Read more.
A trend for the next generation of polymeric dental restoratives is to incorporate multifunctional capabilities to regulate microbial growth and remineralize tooth surfaces. Polymerizable 2-(methacryloyloxy)-N-(2-(methacryloyloxy)ethyl)-N,N-dimethylethan-1-aminium bromide (IDMA1) and N,N′-([1,1′-biphenyl]-2,2′-diylbis(methylene))bis(2-(methacryloyloxy)-N,N-dimethylethan-1-aminium) bromide (IDMA2), intended for utilization in bi-functional antimicrobial and remineralizing composites, were synthesized, purified with an ethanol-diethyl ether-hexane solvent system, and validated by nuclear magnetic resonance (1H and 13C NMR) spectroscopy, mass spectrometry, and Fourier-transform infrared spectroscopy. When incorporated into light-curable urethane dimethacrylate (UDMA)/polyethylene glycol-extended UDMA (PEG-U)/ethyl 2-(hydroxymethyl)acrylate (EHMA) (assigned UPE) resins, IDMAs did not affect the overall resins’ hydrophilicity/hydrophobicity balance (water contact angle: 60.8–65.5°). The attained degrees of vinyl conversion (DVC) were consistently higher in both IDMA-containing copolymers and their amorphous calcium phosphate (ACP) composites (up to 5% and 20%, respectively) reaching 92.5% in IDMA2 formulations. Notably, these high DVCs values were attained without an excessive increase in polymerization stress. The observed reduction in biaxial flexure strength of UPE-IDMA ACP composites should not prevent further evaluation of these materials as multifunctional Class V restoratives. In direct contact with human gingival fibroblasts, at biologically relevant concentrations, IDMAs did not adversely affect cell viability or their metabolic activity. Ion release from the composites was indicative of their strong remineralization potential. The above, early-phase biocompatibility and physicochemical tests justify further evaluation of these experimental materials to identify formulation(s) suitable for clinical testing. Successful completion is expected to yield a new class of restoratives with well-controlled bio-function, which will physicochemically, mechanically, and biologically outperform the conventional Class V restoratives. Full article
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