Navegando por Palavras-chave "Bioactive glass"
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- ItemSomente MetadadadosCharacterization and biocompatibility of a fibrous glassy scaffold(Wiley, 2017) Gabbai-Armelin, Paulo Roberto; Souza, M. T.; Kido, Hueliton Wilian; Tim, Carla Roberta; Bossini, Paulo Sergio [UNIFESP]; Fernandes, Kelly Rossetti [UNIFESP]; Magri, Angela Maria Paiva [UNIFESP]; Parizotto, Nivaldo Antonio; Fernandes, Kristianne Porta Santos; Mesquita-Ferrari, Raquel Agnelli; Ribeiro, Daniel Araki [UNIFESP]; Zanotto, Edgar Dutra; Peitl Filho, Oscar [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]Bioactive glasses (BGs) are known for their ability to bond to living bone and cartilage. In general, they are readily available in powder and monolithic forms, which are not ideal for the optimal filling of bone defects with irregular shapes. In this context, the development of BG-based scaffolds containing flexible fibres is a relevant approach to improve the performance of BGs. This study is aimed at characterizing a new, highly porous, fibrous glassy scaffold and evaluating its in vitro and in vivo biocompatibility. The developed scaffolds were characterized in terms of porosity, mineralization and morphological features. Additionally, fibroblast and osteoblast cells were seeded in contact with extracts of the scaffolds to assess cell proliferation and genotoxicity after 24, 72 and 144 h. Finally, scaffolds were placed subcutaneously in rats for 15, 30 and 60 days. The scaffolds presented interconnected porous structures, and the precursor bioglass could mineralize a hydroxyapatite (HCA) layer in simulated body fluid (SBF) after only 12 h. The biomaterial elicited increased fibroblast and osteoblast cell proliferation, and no DNA damage was observed. The in vivo experiment showed degradation of the biomaterial over time, with soft tissue ingrowth into the degraded area and the presence of multinucleated giant cells around the implant. At day 60, the scaffolds were almost completely degraded and an organized granulation tissue filled the area. The results highlight the potential of this fibrous, glassy material for bone regeneration, due to its bioactive properties, non-cytotoxicity and biocompatibility. Future investigations should focus on translating these findings to orthotopic applications. Copyright (c) 2015 John Wiley & Sons, Ltd.
- ItemSomente MetadadadosCharacterization and biological evaluation of the introduction of PLGA into biosilicate(Wiley, 2017) Fernandes, Kelly Rossetti [UNIFESP]; Magri, Angela Maria Paiva [UNIFESP]; Kido, Hueliton Wilian [UNIFESP]; Ueno, Fabio Roberto [UNIFESP]; Assis, Livia [UNIFESP]; Fernandes, Kristianne Porta Santos; Mesquita Ferrari, Raquel Agnelli; Martins, V. C.; Plepis, Ana M.; Zanotto, Edgar Dutra; Peitl Filho, Oscar; Ribeiro, Daniel Araki [UNIFESP]; Van den Beucken, Jeroen J.; Renno, Ana Claudia Muniz [UNIFESP]The aims of this study were to characterize different BS/PLGA composites for their physicochemical and morphological characteristics and evaluate the in vitro and in vivo biological performance. The physicochemical and morphological modifications were analyzed by pH, mass loss, XRD, setting time, and SEM. For in vitro analysis, the osteoblast and fibroblast viability was evaluated. For in vivo evaluations, histopathology and immunohistochemistry were performed in a tibial defect in rats. After incubation, all composites presented lower values in pH and mass loss over time. Moreover, XRD and SEM analysis confirmed that the composites degraded over time. Additionally, pore formation was observed by SEM analysis after incubation mainly in BS/PLGA groups. BS/PLGA showed significantly increased in osteoblast viability 24 h. Moreover, BS/PLGA composites demonstrated an increase in fibroblast viability in all periods analyzed when compared to BS. In the in vivo study, after 2 and 6 weeks of implantation of biomaterials, histopathological findings revealed that the BS/PLGA composites degrades over time, mainly at periphery. Moreover, can be observed the presence of granulation tissue, bone formation, Runx-2, and RANKL immunoexpression in all groups. In conclusion, BS/PLGA composites present appropriate physicochemical characteristics, stimulate the cellular viability, and enhance the bone repair in vivo. (C) 2016 Wiley Periodicals, Inc.
- ItemSomente MetadadadosIncorporation of bioactive glass in calcium phosphate cement: An evaluation(Elsevier B.V., 2013-03-01) Renno, Ana Claudia Muniz [UNIFESP]; van de Watering, F. C. J.; Nejadnik, M. R.; Crovace, Murilo Camuri; Zanotto, Edgar Dutra; Wolke, J. G. C.; Jansen, J. A.; van den Beucken, Jeroen J. J. P.; Radboud Univ Nijmegen; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de São Carlos (UFSCar)Bioactive glasses (BGs) are known for their unique ability to bond to living bone. Consequently, the incorporation of BGs into calcium phosphate cement (CPC) was hypothesized to be a feasible approach to improve the biological performance of CPC. Previously, it has been demonstrated that BGs can successfully be introduced into CPC, with or without poly(D,L-lactic-co-glycolic) acid (PLGA) microparticles. Although an in vitro physicochemical study on the introduction of BG into CPC was encouraging, the biocompatibility and in vivo bone response to these formulations are still unknown. Therefore, the present study aimed to evaluate the in vivo performance of BG supplemented CPC, either pure or supplemented with PLGA microparticles, via both ectopic and orthotopic implantation models in rats. Pre-set scaffolds in four different formulations (1: CPC; 2: CPC/BG; 3: CPC/PLGA; and 4: CPC/PLGA/BG) were implanted subcutaneously and into femoral condyle defects of rats for 2 and 6 weeks. Upon ectopic implantation, incorporation of BG into CPC improved the soft tissue response by improving capsule and interface quality. Additionally, the incorporation of BG into CPC and CPC/PLGA showed 1.8- and 4.7-fold higher degradation and 2.2- and 1.3-fold higher bone formation in a femoral condyle defect in rats compared to pure CPC and CPC/PLGA, respectively. Consequently, these results highlight the potential of BG to be used as an additive to CPC to improve the biological performance for bone regeneration applications. Nevertheless, further confirmation is necessary regarding long-term in vivo studies, which also have to be performed under compromised wound-healing conditions. (C) 2012 Acta Materialia Inc. Published by Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosIncorporation of bioactive glass in calcium phosphate cement: Material characterization and in vitro degradation(Wiley-Blackwell, 2013-08-01) Renno, Ana Claudia Muniz [UNIFESP]; Nejadnik, M. R.; van de Watering, F. C. J.; Crovace, Murilo Camuri; Zanotto, Edgar Dutra; Hoefnagels, J. P. M.; Wolke, J. G. C.; Jansen, J. A.; van den Beucken, Jeroen J. J. P.; Radboud Univ Nijmegen; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de São Carlos (UFSCar); Eindhoven Univ Technol TU ECalcium phosphate cements (CPCs) have been widely used as an alternative to biological grafts due to their excellent osteoconductive properties. Although degradation has been improved by using poly(D,L-lactic-co-glycolic) acid (PLGA) microspheres as porogens, the biological performance of CPC/PLGA composites is insufficient to stimulate bone healing in large bone defects. in this context, the aim of this study was to investigate the effect of incorporating osteopromotive bioactive glass (BG; up to 50 wt %) on setting properties, in vitro degradation behavior and morphological characteristics of CPC/BG and CPC/PLGA/BG. the results revealed that the initial and final setting time of the composites increased with increasing amounts of incorporated BG. the degradation test showed a BG-dependent increasing effect on pH of CPC/BG and CPC/PLGA/BG pre-set scaffolds immersed in PBS compared to CPC and CPC/PLGA equivalents. Whereas no effects on mass loss were observed for CPC and CPC/BG pre-set scaffolds, CPC/PLGA/BG pre-set scaffolds showed an accelerated mass loss compared with CPC/PLGA equivalents. Morphologically, no changes were observed for CPC and CPC/BG pre-set scaffolds. in contrast, CPC/PLGA and CPC/PLGA/BG showed apparent degradation of PLGA microspheres and faster loss of integrity for CPC/PLGA/BG pre-set scaffolds compared with CPC/PLGA equivalents. Based on the present in vitro results, it can be concluded that BG can be successfully introduced into CPC and CPC/PLGA without exceeding the setting time beyond clinically acceptable values. All injectable composites containing BG had suitable handling properties and specifically CPC/PLGA/BG showed an increased rate of mass loss. Future investigations should focus on translating these findings to in vivo applications. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
- ItemSomente MetadadadosNew highly bioactive crystallization-resistant glass for tissue engineering applications(Lop Publishing Ltd, 2017) Souza, Marina Trevelin; Renno, Ana Claudia Muniz [UNIFESP]; Peitl, Oscar; Zanotto, Edgar DutraBioactive glasses are able to chemically bond to hard and soft tissues and have been proposed and used for tissue regeneration in several dentistry and medical applications. However, the majority of bioactive glass compositions do not support prolonged or repeated heat treatments, since these procedures often result in uncontrolled crystallization, which usually degrade their mechanical properties and, in most instances, substantially diminish their bioactivity. Therefore, the manufacturing of 3D devices, fibers or scaffolds, which aim to expand the usage of these materials, is a challenging task. To overcome this phenomenon, a new bioactive glass composition was recently developed at the Vitreous Materials Laboratory (LaMaV-UFSCar, Brazil) and licensed to the start-up company VETRA. This new bioactive glass composition shows high stability against crystallization coupled with high bioactivity, which allows the development of bioactive fibers, meshes and other complex 3D shapes. In addition, this bioactive glass has an elevated bioactivity, is bioresorbable and flexible (in fiber form), which makes this glass a potential alternative for soft and hard tissue regeneration. In this article, we discuss this recent development and summarize the latest advances in testing the effectiveness of this new material in in vitro and in vivo tests. To date, the results indicate that this new glass composition presents a larger workability window, which allows the development of numerous medical devices. This feature combined with the high bioactivity of this new glass delivers a promising broad spectrum of applications as a material for tissue engineering.