P(MAA-co-AAm)/Fe_3O_4交联磁性复合微球的表征与药物释放研究

磁性高分子微球是利用微胶囊化方法,使有机高分子与无机磁性粒子Fe₃O₄结合起来形成的具有磁响应性的高分子微球.对以聚(甲基丙烯酸-co-丙烯酰胺)(P(MAA-co-AAm))为高分子基材、四氧化三体(Fe₃O₄)为磁性内核通过化学方法制备的 P(MAA-co-AAm)/Fe₃O₄磁性复合微球性能进行了表征.扫描电镜(SEM)照片显示,复合微球呈现明显的交联结构特征,分散性较好.将茶碱负载到P(MAA-co-AAm)/Fe₃O₄磁性交联复合微球上,对其药物释放情况研究表明,在pH值为7.4的碱性缓冲溶液及去离子水中茶碱释放速率较快,在8 h左右达到释放平衡; 而在pH值为1.4的酸性缓冲溶液中,茶碱的释放缓慢,表明P(MAA-co-AAm)/Fe₃O₄磁性复合微球有很好的pH值响应性.因此,载药交联微球在酸性胃液和碱性肠道液中能够自动调节药物释放速率,具有靶向药物释放效果,P(MAA-co-AAm)/Fe₃O₄交联磁性微球可做为靶向药物载体.

The Characterization and Drug Release Behavior Research of P(MAA-co-AAm)/Fe3O4 as Polymer Magnetic Microsphere

Magnetic polymer microsphere is a polymeric microsphere with magnetic response prepared by combining polymers with inorganic magnetic materials Fe₃O₄ based on a microencapsulation method.It can be observed by SEM that P(MAA-co-AAm)/ Fe₃O₄ microspheres have an obvious cross-linked mesh structure with good distribution.The drug controlled release experiment with theophylline indicated that the release rate in pH 7.4 buffer solution and the distilled water were more rapid,and the drug controlled release reach the balance in about 8 hours.However,the drug controlled release rate in pH 1.4 buffer solution is very small,indicated that P(MAA-co-AAm)/ Fe₃O₄ microspheres have obvious pH response,so the crosslinked microspheres loaded drug can automatically adjusted with the drug release rate in acidic gastric juice and alkaline gut,and have the target drug release effect.P(MAA-co-AAm)/Fe₃O₄ crosslinked magnetic microsphere can be used as the target drug delivery carrier.