【摘要】 采用乳液-化学交联法制备磁性氟尿嘧啶壳聚糖微球,重铬酸钾法测定磁性微球中铁含量,古埃磁天平测定磁性微球的磁化率,用SEM测试技术观察了微球的形态;考察了磁性氟尿嘧啶壳聚糖微球在磷酸盐缓冲溶液中的释药性能。结果表明,磁性氟尿嘧啶壳聚糖微球具有强顺磁性,粒径分布1~10μm,Fe3O4质量分数为4.55%~11.44%,药物质量分数为1.86%~9.42%,药物包封率为39.48%~85.30%。体外药物释放实验表明,对氟尿嘧啶的缓释作用明显,释放周期比较长,Fe3O4粒子和含量对微球的释药速率影响不明显;药物释放主要受扩散机制控制,药物含量越大,药物从微球中释放出来的速率越快,可作为理想的磁靶向药物控释体系。更多还原

【Abstract】 Magnetic fluorouracil-loaded chitosan microspheres were prepared by an emulsion chemical-crosslinking method.The Fe content was determined by titration with K₂Cr₂O₇.The magnetic susceptibility was measured by means of a（magnetic） balance,and the morphologies of the magnetic microspheres were （observed） under a scanning electron microscope.The results demonstrate that the magnetic fluorouracil-loaded chitosan microspheres exhibited strong paramagnetism with 4.55%¹1.44%（mass fraction） of Fe₃O₄,1.86%⁹.42%（mass fraction） of FU,39.48%⁸5.30% of which（encapsulated）,and the diameters were in the range of 1¹0 μm.The drug releasing property was studied in the phosphate buffer（pH=7.4）（solution）,and the results show that FU could be released slowly from the microspheres with a longer release period;the content of Fe₃O₄ has an unconspicuous effect on drug release,and drug release was controlled by diffusion mechanism,and the drug releasing from the microspheres became faster with the increase of the drug content.The magnetic fluorouracil-loaded chitosan microspheres are a potential candidate as magnetic-（targeting） system for drug-controlled release.更多还原