RAFT聚合制备一种新型的pH敏感胶束  

Preparation of a New Type of pH-sensitive Micelles by RAFT Polymerization

作　　者：马敏[1] 苑莹芝 张丹[1] 袁建超[1] 

机构地区：[1]西北师范大学化学化工学院,甘肃兰州730070

出　　处：《广东化工》2016年第18期9-11,8,共4页Guangdong Chemical Industry

基　　金：国家自然科学基金资助项目(21364011;20964003)

摘　　要：采用可逆加成-断裂链转移自由基聚合(RAFT)制备一种可生物降解的以腙键(hydrazone)连接的聚N-(2-羟丙基)甲基丙烯酰胺-腙键-聚己内酯(PHPMA-hyd-PCL)两亲性聚合物。运用核磁共振(1H NMR)对聚合物的结构进行了表征。采用透析法制备胶束,形成以聚HPMA为亲水壳层、聚己内酯为疏水内核、腙键为pH敏感基团的胶束。动态光散射(DLS)以及透射电镜(TEM)结果表明,聚合物胶束呈规整球形且分布均匀,平均粒径约为100 nm。以抗癌药物阿霉素作为模型药物模拟体外释放实验,结果表明负载阿霉素的PHPMA64-hyd-PCL80聚合物纳米胶束在pH=7.4的缓冲溶液中48 h累积释放率仅为16%,在缓冲溶液pH=5.0中24 h可以释放85%。在pH=5.0时,由于腙键的断裂,载药胶束显著溶胀增大,抗癌药物迅速从胶束中释放出来,证明该纳米胶束具有较好的药物促释能力。因此,该pH敏感胶束具有作为药物载体的良好潜能。A biodegradable amphiphilic polymer poly（hydroxypropylmethacrylate）-hydrazone-poly（ε-caprolate） （PHPMA-hyd-PCL） containing hydrazone bonds was synthesized by reversible addition-fragmentation chain transfer （RAFT）. The polymer was characterized by proton nuclear magnetic resonance （^2H NMR）. The PHPMA64-hyd-PCL80 polymer was subsequently self-assembled into nanosized micelles with PHPMA as hydrophilic shell, PCL as hydrophobic core and hydrazone bonds as pH sensitive bond. The results of transmission electron microscopy （TEM） and dynamic light scattering （DLS） showed that polymer micelles were regular spheres, particle distributed well and the average particle size was about 100 nm. The in vitro release results （measured by UVNis spectroscopy） showed that 85 % of DOX was released from DOX-loaded PHPMA64-hyd-PCL80 micelles at pH 5.0 in 24 h, however, only 16 % of DOX was released from DOX-loaded PHPMA64-hyd-PCL80 micelles at physiological pH in 48 h. DOX was released from the micelles due to the cleavage of hydrazone bond and swelling of micelles. It demonstrated that the micelles had good controlled release ability. Therefore, the study suggests that the pH sensitive micelles have great potential as controlled drug delivery systems.

关 键 词：RAFT聚合 两亲性聚合物 PH敏感 胶束 

分 类 号：O632[理学—高分子化学]