| dc.description.abstract | Abstract
A novel chitin-based microsphere was developed for drug-delivery purpose in the present study. These biodegradable microspheres were prepared by directly blending chitin with poly(D,L-lactide-co-glycolide ) (PLGA) in DMAc-LiCl solution, followed by being coagulated in water via wet phase inversion. Three condition of the experiment were employed:chitin has blended with different contents of PLGA, and blending solution has been coagulated in water with different temperature, and chitin has blended with different copolymer composition ratio of PLGA. The physicochemical properties of chitin/PLGA blend microspheres were studied by water uptake capacity, in vitro degradation test, SEM, DSC, XRD, and FTIR.
SEM micrography of the blend microsphere showed that there are numerous PLGA particulates homogeneously dispersed in chitin matrix, suggesting the occurrence of obvious phase separation from the blended chitin and PLGA phase. The distribution of PLGA in chitin matrix has been improved by higher water temperature. From SEM observed, the well-distributed properties of PLGA in chitin/PLGA microspheres were increased with higher water temperature. Weight loss of the chitin/PLGA blend microsphere increases with the increase of chitin content in the microsphere, and also increases with the increase of glycolide composition ratio of PLGA. Degradation of the chitin/PLGA blend microsphere depends on the surface erosion of chitin phase and bulk hydrolysis of PLGA phase, according to the examinations of SEM and DSC studies. Two-phase drug release model is observed from the release of chlorambucil from chitin/PLGA blend microspheres. The initial stage of fast drug-release rate increases with the increased chitin content, the followed stage of slow release is sustained for several days. However, the release of Albumin from chitin/PLGA blend microspheres in different water temperature series and different copolymer ratio of PLGA series also have two-stage release model, but the initial stage has slowly release rate that increases with raising water temperature during preparing process, and the different copolymer composition ratio of PLGA also has effect on the protein release rate; the followed stage has fast release rate and sustained for 14 days. | en_US |