PNIPA/PEG多孔水凝胶的溶胀与药物释放性能

Swelling and drug release properties of PNIPA/PEG porous hydrogels

以N-异丙基丙烯酰胺(N-isopropyl acrylamide,NIPA)为单体,聚乙二醇(Poly(ethylene glycol),PEG)为成孔剂,N,N-亚甲基双丙烯酰胺(N,N-methylene-bis-acrylamide,MBA)为交联剂,采用辐射聚合法制备出了一系列具有合适相转变温度的聚N-异丙基丙烯酰胺/聚乙二醇(Poly(N-isopropyl acrylamide)/Poly(ethyleneglycol),PNIPA/PEG)快速响应多孔智能水凝胶。用扫描电镜分析了该材料的表面形貌,研究了NIPA含量和PEG分子量对溶胀性能的影响,并以阿司匹林为模型药物研究了药物释放性能。结果表明:在该材料中存在大量孔洞,而未加成孔剂的水凝胶表面较为致密;该材料的溶胀率和失水率随NIPA含量的增大而逐渐减小,较低临界溶解温度(Lower critical solution temperature,LCST)和释药率都随PEG分子量的增大而逐渐增大,在PEG分子量为6000时,多孔水凝胶37℃下的释药率大于25℃,释药都符合Fickian扩散模式。

A series ofPNIPA/PEG （poly （N-isopropyl acrylamide）/poly （ethylene glycol）） porous intelligent hy- drogels, which exhibited appropriate phase transition temperature and fast response behavior, were synthesized by ra- diation polymerization with NIPA （N-isopropyl acrylamide） as monomer, PEG （poly （ethylene glycol）） as pore-forming agent and MBA （N, N-methylene-bis-acrylamide） as crosslinking agent. The surface morphology of the material was examined by the scanning electron microscopy. The influences of NIPA content and PEG molecular weight on swelling properties were discussed. Drug release properties were studied with aspirin as a model drug. The results showed that macropores were observed in the sample, whereas hydrogels prepared without using PEG had a dense surface. The swelling ratio and water loss ratio of the sample decreased with increment of NIPA content. LCST （Lower critical solution temperature） and the release ratio increased with PEG molecular weight. The release ratio of PNIPA/PEG6000 hydrogel at 37℃ was larger than that at 25℃ and the release mechanism could be described with Fickian diffusion type.