The fabrication and related properties study of chitosan-poly (lactide-co-glycolide) double-walled microspheres loaded with nerve growth factor

To evaluate the feasibility of the chitosan-poly (lactide-co-glycolide) (PLGA) double-walled microspheres for sustained release of bioactive nerve growth factor (NGF) . NGF loaded chitosan-PLGA double-walled microspheres were prepared by emulsion-ionic method with sodium tripolyphosphate (TPP) as an ionic cross-linker. The double-walled microspheres were cross-linked by different concentrations of TPP [1%, 3%, 10% ( / )]. NGF loaded PLGA microspheres were also prepared. The outer and inner structures of double-walled microspheres were observed by light microscopy, scanning electron microscopy, confocal laser scanning microscopy, respectively. The size and distribution of microspheres and fourier transform infra red spectroscopy (FT-IR) were analyzed. PLGA microspheres with NGF or chitosan-PLGA double-walled microspheres cross-linked by 1%, 3%, and 10%TPP concentration (set as groups A, B, C, and D respectively) were used to determine the degradation ratio of microspheres and the sustained release ratio of NGF