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1.
Polylactic acid-based porous scaffolds doped with calcium silicate and dicalcium phosphate dihydrate designed for biomedical application.
Gandolfi, MG, Zamparini, F, Degli Esposti, M, Chiellini, F, Aparicio, C, Fava, F, Fabbri, P, Taddei, P, Prati, C
Materials science & engineering. C, Materials for biological applications. 2018;:163-181
Abstract
Polylactic acid (PLA), dicalcium phosphate dihydrate (DCPD) and/or hydraulic calcium silicate (CaSi) have been used to prepare highly-porous scaffolds by thermally induced phase separation technique (TIPS). Three experimental mineral-doped formulations were prepared (PLA-10CaSi, PLA-5CaSi-5DCPD, PLA-10CaSi-10DCPD). Pure PLA scaffolds constituted the control group. Scaffolds were tested for their chemical-physical and biological properties, namely calcium release, alkalinizing activity, surface microchemistry and micromorphology by ESEM, apatite-forming ability by EDX, micro-Raman and IR spectroscopy, thermal properties by differential scanning calorimetry, mechanical properties by quasi-static parallel-plates compression testing, porosity by a standard water-absorption method and direct-contact cytotoxicity. All mineral-doped scaffolds released biologically relevant ions (biointeractive). A B-type carbonated apatite layer (thickness decreasing along the series PLA-10CaSi-10DCPD>PLA-10CaSi>PLA-5CaSi-5DCPD>PLA) was detected on the surface of all the 28d-aged scaffolds. Surface pores of fresh scaffolds ranged from 10 to 20μm in pure PLA to 10-100μm in PLA-10CaSi. An increase in porosity was detected in 28d-aged pure PLA scaffolds (approx. 30% of material loss with decrease of the PLA chain length); differently, in mineral-doped scaffolds, the PLA degradation was balanced by deposition/nucleation of apatite. All scaffolds showed absence of toxicity, in particular PLA-10CaSi-10DCPD. The designed scaffolds are biointeractive (release biologically relevant ions), nucleate apatite, possess high surface and internal open porosity and can be colonized by cells, appearing interesting materials for bone regeneration.
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2.
Mesoporous bioactive glasses: Promising platforms for antibacterial strategies.
Kargozar, S, Montazerian, M, Hamzehlou, S, Kim, HW, Baino, F
Acta biomaterialia. 2018;:1-19
Abstract
The control of bacterial infections is of particular importance in the field of tissue engineering. Recently, much attention has been addressed toward the use of mesoporous bioactive glasses (MBGs) for antibacterial strategies, primarily because of their capability of acting as carriers for the local release of antimicrobial agents. The incorporation of antibacterial metallic ions including silver (Ag+), zinc (Zn2+), copper (Cu+ and Cu2+), cerium (Ce3+ and Ce4+), and gallium (Ga3+) cations into the MBG structure and their controlled release is proposed as one of the most attractive strategies for inhibiting bacterial growth and reproduction. Moreover, the possibility of loading and delivering various antibacterial biomolecules (e.g., antibiotics) through the porous structure of MBGs makes them as ideal candidates for antibacterial applications. In this review, we aim to present a comprehensive evaluation of MBG potential regarding antibacterial activities. For this purpose, different types of antibacterial ion-doped and drug-loaded MBGs are introduced and discussed in the light of existing knowledge, along with the significant challenges ahead. STATEMENT OF SIGNIFICANCE Prevention and treatment of infections is one of the today's greatest challenges in medical sciences, also considering the well-known issues related to increased bacterial resistance to antibiotics. The advent of mesoporous glasses led to the birth of a new class of multifunctional biomaterials acting as bioactive platforms for the local release of organic or inorganic agents eliciting an antimicrobial effect. This reviews summarizes the state of the art of MBGs in this field, highlighting the latest evolutions and the specific role played by metallic antimicrobial ions that can be incorporated in the glass composition and then properly released. Perspective for tissue engineering applications are also discussed to provide an up-to-date contribution that is useful to both experienced scientists and early-stage researchers.
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3.
Mg-Zn alloys, most suitable for biomedical applications.
Bîrcă, AC, Neacşu, IA, Vasile, OR, Ciucă, I, Vasile, IM, Fayeq, MA, Vasile, BŞ
Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie. 2018;(1):49-54
Abstract
In this review are highlighted the corrosion and biocompatibility of biodegradable Mg alloys for their use in orthopedic applications. It was revealed that mixing with alloying elements, such as Mn and Zn, provides improved corrosion resistance to Mg alloys; this pursuit is built on the fact that Mg and its alloys are degradable through their time in the human body. Furthermore, Mg alloys afford a characteristic profile that is very close or even almost identical to that of human bone. Minimizing the rate of corrosion of Mg is the most adequate method, because a low corrosion rate of an Mg implant involves a decrease in the extent of hydrogen evolution and alkalization, which allow the human body to gradually absorb or consume the corrosion products.
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4.
Alternatives to Autologous Bone Graft in Alveolar Cleft Reconstruction: The State of Alveolar Tissue Engineering.
Liang, F, Leland, H, Jedrzejewski, B, Auslander, A, Maniskas, S, Swanson, J, Urata, M, Hammoudeh, J, Magee, W
The Journal of craniofacial surgery. 2018;(3):584-593
Abstract
Alveolar cleft reconstruction has historically relied on autologous iliac crest bone grafting (ICBG), but donor site morbidity, pain, and prolonged hospitalization have prompted the search for bone graft substitutes. The authors evaluated bone graft substitutes with the highest levels of evidence, and highlight the products that show promise in alveolar cleft repair and in maxillary augmentation. This comprehensive review guides the craniofacial surgeon toward safe and informed utilization of biomaterials in the alveolar cleft.A literature search was performed to identify in vitro human studies that fulfilled the following criteria: Level I or Level II of evidence, ≥30 subjects, and a direct comparison between a autologous bone graft and a bone graft substitute. A second literature search was performed that captured all studies, regardless of level of evidence, which evaluated bone graft substitutes for alveolar cleft repair or alveolar augmentation for dental implants. Adverse events for each of these products were tabulated as well.Sixteen studies featuring 6 bone graft substitutes: hydroxyapatite, demineralized bone matrix (DBM), β-tricalcium phosphate (TCP), calcium phosphate, recombinant human bone morphogenic protein-2 (rhBMP-2), and rhBMP7 fit the inclusion criteria for the first search. Through our second search, the authors found that DBM, TCP, rhBMP-2, and rhBMP7 have been studied most extensively in the alveolar cleft literature, though frequently in studies using less rigorous methodology (Level III evidence or below). rhBMP-2 was the best studied and showed comparable efficacy to ICBG in terms of volume of bone regeneration, bone density, and capacity to accommodate tooth eruption within the graft site. Pricing for products ranged from $290 to $3110 per 5 mL.The balance between innovation and safety is a complex process requiring constant vigilance and evaluation. Here, the authors profile several bone graft substitutes that demonstrate the most promise in alveolar cleft reconstruction.
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5.
Effect of calcium ions on peptide adsorption at the aqueous rutile titania (110) interface.
Sultan, AM, Hughes, ZE, Walsh, TR
Biointerphases. 2018;(6):06D403
Abstract
How the presence of Ca2+ ions at the aqueous TiO2 interface influences the binding modes of two experimentally identified titania-binding peptides, Ti-1 and Ti-2, is investigated using replica exchange with solute tempering molecular dynamics simulations. The findings are compared with available experimental data, and the results are contrasted with those obtained under NaCl solution conditions. For Ti-1, Ca2+ ions enhance the adsorption of the negatively charged Asp8 residue in this sequence to the negatively charged surface, via Asp–Ca2+–TiO2 bridging. This appears to generate a nonlocal impact on the adsorption of Lys12 in Ti-1, which then pins the peptide to the surface via direct surface contact. For Ti-2, fewer residues were predicted to adsorb directly to the surface in CaCl2, compared with predictions made for NaCl solution, possibly due to competition between the other peptide residues and Ca2+ ions to adsorb to the surface. This reduction in direct surface contact gives rise to a more extensive solvent-mediated contact for Ti-2. In general, the presence of Ca2+ ions resulted in a loss of conformational diversity of the surface-adsorbed conformational ensembles of these peptides, compared to counterpart data predicted for NaCl solution. The findings provide initial insights into how peptide–TiO2 interactions might be tuned at the molecular level via modification of the salt composition of the liquid medium.
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6.
Randomized, Double-Blinded, Sham-Controlled, Split-Hand Trial Evaluating the Safety and Efficacy of Triamcinolone Acetate Injection After Calcium Hydroxylapatite Volume Restoration of the Dorsal Hand.
Wu, DC, Goldman, MP
Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2018;(4):534-541
Abstract
BACKGROUND Calcium hydroxylapatite (CaHA) is currently the only FDA-approved soft-tissue filler indicated for augmentation of the dorsal hand. Although the treatment is generally safe and effective, adverse side effects such as swelling and edema postinjection are common and can sometimes be debilitating. OBJECTIVE In this study, the authors explore the utility of triamcinolone acetate coinjection with CaHA to the dorsal hands to mitigate adverse effects and improve patient experience. PATIENTS AND METHODS After obtaining informed consent, 20 subjects were enrolled in this double-blind, randomized, split-hand, sham-controlled clinical trial. Subject hands were randomized to receive either CaHA with triamcinolone acetate or CaHA with sham saline coinjection. Follow-up evaluations were performed by a blinded investigator at Days 7, 14, 30, 90, 180, 270, and 360 and consisted of the validated Merz Hand Grading Scale and assessments of erythema, edema, modules, bruising, and skin atrophy. Subjects also kept a daily diary for the first 30 days postinjection documenting bruising, itching, pain, redness, swelling, difficulty in performing activities with hands, and sensory alteration in hands. RESULTS There were no significant differences in treatment efficacy between the 2 groups. Post-treatment swelling was significantly reduced between Days 6 and 19 in the triamcinolone acetate coinjection group. CONCLUSION The addition of triamcinolone acetate coinjection with CaHA for dorsal hand augmentation did not negatively impact treatment efficacy but significantly reduced adverse side effects. This strategy represents a safe and effective way to improve patient experience and treatment tolerability.
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7.
Multiple layers and conjugate materials for food emulsion stabilization.
Sivapratha, S, Sarkar, P
Critical reviews in food science and nutrition. 2018;(6):877-892
Abstract
A single emulsifier material is seldom sufficient to cater to the requirements of complex emulsion-based food formulations that have to function over a wide range of pH, ionic strength, storage time, and temperature. Food emulsions have to be designed to satisfy several requirements for use which could be achieved by combining the beneficial properties of multiple emulsifiers. The present article reviews novel biological materials that are used to design oil-in-water (o/w) emulsions. More specifically, the major focus is to discuss (o/w) interfaces stabilized by multiple biopolymers. Prevalent ways by which two or more emulsifiers could be combined is by (i) forming multi-layered emulsions and (ii) conjugation of two compounds of beneficial traits. Multilayer emulsions make use of a combination of protein, phospholipids, and carbohydrates to stabilize (o/w) interfaces. On the other hand, covalent bonding between a protein and polysaccharide is induced to form a single entity known as conjugate that is superior to the individual biopolymers in terms of emulsion stability. Therefore, properties required to maintain emulsion stability such as surface activity, solubility, steric and electrostatic repulsion, and antioxidant effects from two different hydrocolloids could be integrated.
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8.
Filling Procedures for Lip and Perioral Rejuvenation: A Systematic Review.
Pascali, M, Quarato, D, Carinci, F
Rejuvenation research. 2018;(6):553-559
Abstract
The ideal perioral and lip rejuvenation technique provides the longest period of efficacy, lowest complication rate, and best esthetic results. Genetics, intrinsic aging, sun exposure, and repetitive muscle twitching of the orbicularis oris produce angular, radial, and vertical lines of the perioral lines and, for this reason, the needs of patients in the treatment of this anatomical area can range from simple lip enhancement to a broader and more comprehensive treatment with simultaneous correction of perioral wrinkles. A myriad of materials have been described for rejuvenation of this area. At present, the most popular and commonly used lip enhancers are dermal fillers, but there is still no agreement on what the best material for filling soft tissue of the face and in particular of the perioral region is. This systematic review will focus on the various dermal fillers, of different materials approved by the US Food and Drug Administration (FDA) namely poly-L-lactic acid, calcium hydroxylapatite, and hyaluronic acid and also different grafts, for perioral rejuvenation, with the goal of determining the optimal approach. A systematic search for English studies involving perioral rejuvenation was performed using these databases: PubMed, Google Scholar, and Ovid, using a combined keyword search or medical subject headings. At the end of our study selection process, 17 relevant publications were included. For each study, year of publication, type of material used for filling, number of patients, subject of study assessment, and efficacy of the filler procedure for lip rejuvenation were analyzed.
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9.
Mesoporous silica-based bioactive glasses for antibiotic-free antibacterial applications.
Kaya, S, Cresswell, M, Boccaccini, AR
Materials science & engineering. C, Materials for biological applications. 2018;:99-107
Abstract
Bioactive glasses (BGs) are being used in several biomedical applications, one of them being as antibacterial materials. BGs can be produced via melt-quenching technique or sol-gel method. Bactericidal silver-doped sol-gel derived mesoporous silica-based bioactive glasses were reported for the first time in 2000, having the composition 76SiO2-19CaO-2P2O5-3Ag2O (wt%) and a mean pore diameter of 28nm. This review paper discusses studies carried out exploring the potential antibacterial applications of drug-free mesoporous silica-based BGs. Bioactive glasses doped with metallic elements such as silver, copper, zinc, cerium and gallium are the point of interest of this review, in which SiO2, SiO2-CaO and SiO2-CaO-P2O5 systems are included as the parent glass compositions. Key findings are that silica-based mesoporous BGs offer a potential alternative to the systemic delivery of antibiotics for prevention against infections. The composition dependent dissolution rate and the concentration of the doped elements affect the antibacterial efficacy of BGs. A balance between antibacterial activity and biocompatibility is required, since a high dose of metallic ion addition can cause cytotoxicity. Typical applications of mesoporous BGs doped with antibacterial ions include bone tissue regeneration, multifunctional ceramic coatings for orthopedic devices and orbital implants, scaffolds with enhanced angiogenesis potential, osteostimulation and antibacterial properties for the treatment of large bone defects as well as in wound healing.
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10.
A review on versatile applications of blends and composites of pullulan with natural and synthetic polymers.
Tabasum, S, Noreen, A, Maqsood, MF, Umar, H, Akram, N, Nazli, ZI, Chatha, SAS, Zia, KM
International journal of biological macromolecules. 2018;(Pt A):603-632
Abstract
Pullulan is a non-ionic, linear, water-soluble and a neutral polysaccharide. It is composed of α-(1,6) repeated maltotriose units via α-(1,4) glycosidic bond having chemical formula (C6H10O5)n. It shows non-immunogenic, non-toxic, non-carcinogenic and non-mutagenic properties. It is used in food edible coatings, films, as flocculant, foaming agent and adhesive. It may also be used as a carrier for bioactive compounds and a protective packaging for food and pharmaceutical products. Therefore, it is blended with different polymers such as carrageenan, mucilages, chitosan, cellulose, sodium alginate, starch, polyethyleneimine, whey-protein, polyisopropylacrylamide, histone, jeffamine, polyamidoamine, pemulen, hyaluronic acid, polyvinyl alcohol and caboxymethyl cellulose. In this article, a comprehensive overview of combination of pullulan with natural and synthetic polymers and their applications in biomedical field involving drug delivery system, tissue engineering, wound healing and gene therapy, is presented. It also describes the utilization of pullulan based materials in food industry, water treatment and pharmaceutical industry. All the technical scientific issues have been addressed; highlighting the recent advancements.