5-Fu壳聚糖/丝素复合磁微球的制备及体外性质研究

 目的以壳聚糖/丝素复合高分子为骨架材料，研制5-Fu磁微球的制备，考察其缓释效果和磁响应性。方法 乳化-化学交联法制备微球，动态透析法进行体外释药，离体定位装置进行体外磁定位。结果 壳聚糖/丝素复合材料对5-Fu的包封和缓释效果优于单组分的壳聚糖；随戊二醛用量的增加缓释效果增强，体外释放符合Higuchi方程，Q=2.744 8t^1/2+35.261 3(r=0.965 1)，t₅₀为28.83 h；含12%磁性物质的微球，在磁感应强度0.4 T、介质流速1 cm·s^-1、离磁场距离≤3 cm时，微球在靶区的截留率达75%以上。结论壳聚糖/丝素复合磁微球在药物的缓释和靶向定位方面有潜在的应用价值。

Preparation of 5-fluorouracil loaded chitosan/fibroin blend magnetic microspheres and its properties in vitro

OBJECTIVE To prepare 5-fluorouracil loaded magnetic microspheres with crosslinked chitosan and silk fibroin blend as the novel natural biodegradable wall materials and investigate their sustained release and magnetic responsive properties. METHODS The microspheres were prepared by emulsion cross linking techniques.The release test of 5-Fu from magnetic CS/FB microspheres in vitro was carried out using constant temperature vibration dialysis assay.Magnetic responsive property was investigated using the apparatus of magnetic guidance experiment in vitro. RESULTS The sustained release and trapping efficiency of chitosan/ fibroin blend microspheres were better than those of chitosan microspheres.The release of 5-Fu from microspheres was decreased along with increased glutaraldehyde concentration.The drug release profile was described by Higuchi equation Q=2.744 8t^1/2+35.2613 (r=0.9651)，t₅₀=28.83 h.Under the condition of magnetic restonsive intensity 0.4 T,medium flowing speed 1 cm·s^-1,distance from the target site ≤3 cm,the accumulation percentage of microspheres containing 12% magnetite at the target site was above 75%. CONCLUSION Chitosan/fibroin blend magnetic microspheres may have potential application prospects in 5-Fu sustained release and targeted localization.