Navegando por Palavras-chave "nanofibers"

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    Biomateriais na reparação do sistema nervoso central: uso de nanofibras sintéticas biodegradáveis como suporte para transplante celular e nanopartículas contendo cxcl12 no recrutamento de células-tronco endógenas
    (Universidade Federal de São Paulo (UNIFESP), 2016-12-31) Zamproni, Laura Nicoleti [UNIFESP]; Porcionatto, Marimelia Porcionatto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Central nervous system (CNS) disorders are highly debilitating and with few therapeutic options. Stem cells are a therapeutic promise for these diseases. The two main strategies described in literature are exogenous stem cells transplantation and enhancement of endogenous neurogenesis. Since both strategies pose problems, there is increasing research on the use of biomaterial to try to optimize cell engraftment and delivery of soluble factors that can increase neurogenesis. In this study, we evaluated polylactic acid (PLA) polymeric nanofibers (PNF) as carriers for cell transplantation and evaluated two formulations of poly(lactic-co-glycolic acid) (PLGA) for local delivery of CXCL12, a powerful chemokine to recruit neural stem cells (NSC). PNF were produced by jet-rotatory spinning and characterized by scanning electron microscopy. MSC and NSC obtained respectively from bone marrow and subventricular zone of C57BL/6 adult mice were cultured on PNF and transplanted into the brain of adult mice submitted to ischemic stroke model. Both cell types were viable when cultured on PNF, and MSC but not NSC were able to reduce the necrotic area. CXCL12 formulations were made by double emulsion. Two formulations were evaluated: microspheres (MS) and nanoparticles (NP). Both were able to encapsulate more than 80% of CXCL12, but showed different release profiles, with 100% CXCL12 released after 6 days for MS and 25% CXCL12 released after 2 weeks for NP. CXCL12 bioactivity was demonstrated by chemotaxis assay. When injected into the brains of mice submitted to traumatic brain injury model, only NP-CXCL12 induced CTN migration to the injured area. We conclude that the PNF are viable scaffolds for cell transplantation, MS and NP are suitable for soluble factor, such as CXCL12, delivery in two different brains injury model. Thus, we suggest that both approaches presented in this work could be tested as therapeutic strategies for CNS injuries.