碳纳米管复合海藻酸微球药物载体的释药性能

Drug-Release Property of Carbon Nanotube-Loaded Alginate Microspheres as Drug Carrier

利用PEO137-b-PPO44-b-PEO137三嵌段聚合物促进碳纳米管在溶液中的分散,进而制备出碳纳米管复合海藻酸微球药物载体.碳纳米管的引入对海藻酸微球的结构与形态无明显影响,但有效地提高了其稳定性,药物包封率从76.5%提高到89.2%.进一步研究发现碳纳米管复合海藻酸微球的溶胀行为和药物释放行为继承了海藻酸的pH敏感性,在胃pH 1.0环境中溶胀度仅为约76%,而在肠和结肠pH环境中溶胀度可达到2 000%以上甚至溶蚀,适合于用作肠和结肠中的药物控制释放.同时,碳纳米管的引入能够有效地降低药物的释放速率,提高缓释效果,而且不会额外地增加载体的细胞毒性.

The triblock copolymer,PEO137-b-PPO44-b-PEO137,was used to improve the dispersion of carbon nanotube（CNT） in aqueous solution,and hence fabricated a kind of complex drug carrier based on CNT and alginate（AL）.The introducing of CNT had no obvious effect on the structure and morphology of the alginate microsphere,but enhanced its stability and increased the encapsulation efficiency from 76.5% to 89.2%.The AL/CNT microspheres inherited the pH dependence of swelling and drug-release,namely the swelling degree was only ca.76% in the pH1.0 of stomach condition and reached the above 2 000% in the pH condition of intestine and colon.This was suitable to controlled-release（the control and release of） the drug in intestine and colon.Especially,the addition of CNT could efficiently decrease the release ratio of drug,i.e.improving the effect of sustaining release.In addition,the CNT could not increase the additional cytotoxicity.