bFGF缓释微球的制备及其促雪旺细胞分裂增殖的初步研究

研究碱性成纤维细胞生长因子(bFGF)缓释微球的制备方法及其对雪旺细胞的促分裂增殖作用。以聚乳酸-羟基乙酸共聚物(PLGA)为载体材料,采用复乳包囊法制备bFGF-PLGA缓释微球,并对微球的形态学、粒径分布、载药量和包封率、及体外释药进行研究。将bFGF、bFGF-PLGA微球分别加入不同组的雪旺细胞培养液中,分别测定雪旺细胞的数量、活力和细胞周期。结果显示,复乳包囊法制备的bFGF-PLGA缓释微球表面光滑圆整,球体均匀度好;微球平均粒径为1.552±0.015μm,平均径距为1.310±0.010;载药量和包封率分别为(27.18×10-3)%±(0.51×10-3)%、66.43%±1.24%;微球的体外释药过程较为稳定,11d释药率为72.47%。体外细胞试验中,培养1、2d时,bFGF组的细胞计数、吸光度明显高于bFGF缓释微球组;培养3、4d时,bFGF组和bFGF缓释微球组的细胞计数、吸光度无统计学差异;培养6、8d时,bFGF缓释微球组的细胞计数、吸光度明显高于bFGF组。流式细胞仪检测结果显示,培养2d后,bFGF组的G2/M S期百分数高于bFGF缓释微球组;培养4、8d后,bFGF缓释微球组的G2/M S期百分数高于bFGF组,差异具有统计学意义。说明采用复乳包囊法制备bFGF-PLGA缓释微球的工艺可行,微球中bFGF的生物活性保存良好,能缓慢持续释放活性bFGF,促进雪旺细胞的分裂增殖。

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.