[Preparation of controlled release microsphere incorporating bFGF and its effect on Schwann cells]

To study the preparation method of bFGF microspheres and to investigate the bioactivities of bFGF, which were released from the bFGF microspheres, on the cultured schwann cells. bFGF was microcapsulated with the multiple emulsion encapsulative method using PLGA as coating material. Its morphology, particle size distribution, drug loading-embedding rate and in vitro release property were studied. The cultured schwann cells were grouped according to the different ingredients being added to the culture medium: bFGF group, bFGF-PLGA group. Then the number, the viability and the cell cycle of schwann cells were measured. The morphology and the particle size distribution of the bFGF-PLGA microspheres were even and good; the drug-loading and drug-embedding rate of microspheres were (27.18 x 10(-3)) % +/- (0.51 x 10(-3)) %, 66. 43% +/- 1.24%; the release property of microspheres in vitro was good and the overall release rate was 72. 47% in 11 days. The in vitro cellular study showed: 1, 2 days after plate culture, the cell number and cell viability of bFGF group was much better than that of bFGF-PLGA group; 3, 4 days after plate culture, the cell number and cell viability of bFGF group and bFGF-PLGA group were not different statistically; 6, 8 days after plate culture, the cell number and cell viability of bFGF-PLGA group was much better than that of bFGF group. Through the flow cytometry examination: 2 days after plate culture, the GJ/M+S percentage of bFGF group was higher than that of bFGF-PLGA group; 4, 8 days after plate culture, the G2/M+S percentage of bFGF-PLGA group was higher than that of bFGF group. So, it is practical to prepare the bFGF-PLGA microspheres with the multiple emulsion encapsulative method. bFGF-PLGA microspheres can preserve the bioactivities of bFGF effectively and promotes the proliferation of schwann cells in a long period because of the controlled release of bFGF from microspheres.