Preparation and in vitro release properties of bFGF-loaded chitosan microspheres

Objective:To prepare basic fibroblast growth factor(bFGF) loaded chitosan microspheres,and to analyze the property of controlled release of bFGF in vitro.Methods: Firstly,chitosan blank microspheres were prepared with emulsification cross-linking method,then bFGF-loaded chitosan microspheres were prepared by the chitosan blank microspheres absorbing bFGF.The microspheres were observed by scanning electron microscopy,and the drug loading,encapsulation efficiency and in vitro controlled release of the bFGF-loaded chitosan microspheres were measured by ELISA.Furthermore,the water absorption expansion rate of microspheres were measured.Results: The mean diameter of the bFGF-loaded chitosan microspheres was about 4 μm,and the drug loading and encapsulation efficiency of the bFGF-loaded chitosan microspheres were 1.06 μg/mg and 84.8%,respectively.The microspheres released quickly at initial 12 hours,and then slowed gradually in vitro.The absorbing water expansion rate of the blank microspheres was 650%.Conclusion: Chitosan microspheres encapsulating bFGF prepared by emulsification cross-linking method exhibit high yield and good controlled-release effect.