PLGA (poly(lactic-co-glycolic) acid)-PEG (polyethylene glycol)-PLGA synthesis conditions have an impact on the physicochemical features of the copolymer and its usefulness as biomaterial. This study reports on an analysis of the composition and structural properties of PLGA-PEG-PLGA copolymers applying a variety of analytical techniques. Viscoelastic properties and particularly the temperature-responsive behavior of PLGA-PEG-PLGA showed a marked dependence on copolymer structural features.
View Article and Find Full Text PDFIn this study a poly(lactide-co-glycolide) acid (PLGA) tri-layer scaffold is proposed for cartilage repair. The trilayer system consists of a base layer formed by a tablet of PLGA microspheres, a second layer composed of a microsphere suspension placed on top of the tablet, and the third layer, which constitutes an external electrospun PLGA thin polymeric membrane. Combinations of bone morphogenetic protein-2 (BMP-2) encapsulated in the microspheres of the suspension layer, and bone marrow mesenchymal stem cells (bMSC) seeded on the electrospun membrane, are evaluated by histologic analyses and immunohistochemistry in a critical size osteochondral defect in rabbits.
View Article and Find Full Text PDFThe aim of this work was to study the bone repair induced by bone morphogenetic protein-2 (BMP-2), rat mesenchymal stem cells (rMSCs), and platelet-derived growth factor (PDGF-BB) incorporated in a macroporous beta-tricalcium phosphate (β-TCP) system fabricated by robocasting, and to identify the most beneficial combination in a critical rat calvaria defect. BMP-2 was formulated in microspheres to provide a prolonged, local concentration, whereas PDGF-BB, which acts during the initial stage of defect repair, was incorporated in a thin layer of crosslinked alginate. Approximately 80% of PDGF-BB and 90% of BMP-2 were released into the defect during the first 2 d and 3 weeks, respectively.
View Article and Find Full Text PDFIn this study, three systems containing BMP-2 were fabricated, including two electrospun sandwich-like-systems of PLGA 75:25 and PLGA 50:50 and a microsphere system of PLGA 50:50 to be implanted in a critical size defect in rat calvaria. The in vivo BMP-2 release profiles of the three systems were similar. The total dose was released during the first two weeks.
View Article and Find Full Text PDFA sandwich-like system, fabricated with electrospun, poly(lactic-co-glycolic-acid) (PLGA) membranes incorporating either human recombinant bone morphogenetic protein 2 (BMP-2) enriched microspheres, rat bone marrow mesenchymal stem cells (rMSC), or rMSC with their Smurf1 (SMAD ubiquitin regulatory factor-1) expression knocked down by means of siRNA (rMSC573) at varying densities was evaluated in a rat calvarial, critical-size defect. The behavior of four membrane varieties, fabricated with different PLGA copolymers, was initially studied in rMSC cultures to decide on optimal membrane degradation and cell proliferation and differentiation characteristics. PLGA75:25 provided the most stable structure, and favored the cell environment.
View Article and Find Full Text PDFCurrent wired telemedicine systems encounter difficulties when implemented in archipelagic developing countries because of the high cost of fixed infrastructure. In this research, we devised Lifelink, a mobile real-time telemonitoring and diagnostic facility to command and control remote medical devices through mobile phones. The whole process is phone-based, effectively freeing offsite medical specialists from stationary monitoring consoles and endowing the system with the potential to increase the number participating consultants.
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