pH响应性聚合物修饰的空心介孔硅球的制备

Facile Preparation of Hollow Mesoporous Silica Nanoparticles Coated with pH-Sensitive Polymer

将有机硅RAFT试剂三甲氧基硅基丙基三硫代羰基苄基酯(BTPT)固载于硅球表面,通过可逆加成-断裂链转移自由基聚合表面接枝法制备了pH值、温度双敏感聚合物聚甲基丙烯酸-2-(二甲氨基)乙酯(PDMAEMA)修饰的纳米硅球,通过表面保护法在常温下用氨水对该修饰过的硅球进行刻蚀,制得PDMAEMA修饰的纳米空心介孔硅球(HMS@PDMAEMA)。通过核磁、红外、GPC和透射电子显微镜等方法对其结构和表面形貌进行了表征,并用纳米粒度及zeta电位仪测试了其pH值响应行为,预测HMS@PDMAEMA在癌症药物的控制释放和基因递送等领域具有潜在的应用价值。

Trimethoxysilyl-propyl-trithiocarbonyl-benzyl ester（BTPT） , which is one of the silicone-based RAFT agents, was grafted onto the surface of silica nanospheres. Using the reversible addition-fragmenta- tion chain transfer polymerization, silica nanospheres modified with the pH-and temperature-sensitive polyelectrolyte poly（N, N-dimethylaminoethyl methacrylate） （PDMAEMA） were prepared. Then silica nanospheres grafted with PDMAEMA were transformed to the hollow mesoporous structure by surface-protected etching strategy using ammonia at ambient temperature, thereby obtained the hollow mesoporous silica nanospheres modified with the PDMAEMA （HMS@ PDMAEMA）. The resultant composite nanop- articles with pH-and temperature-sensitive polymer shell and HMS core were characterized by a variety of techniques such as 1HNMR, FTIR, GPC and TEM, etc. The pH-sensitive behavior was tested by nano- size and zeta potential analyzer. We envision that the HMS@ PDMAEMA should have potential applica- tions in controlled release of anticancer drug and gene delivery.