pH敏感性水凝胶P(MAPOSS-co-AA)的制备及药物缓释性能

Synthesis and Drug Release Property of P(MAPOSS-co-AA) pH-Sensitive Hydrogels

以丙烯酸(AA)和七苯基甲基丙烯酰氧基笼型倍半硅氧烷(MAPOSS)为单体,以偶氮二异丁腈为催化剂,N,N-亚甲基丙烯酰胺为交联剂,通过自由基溶液聚合法,制备了具有pH敏感性的有机-无机共聚水凝胶P(MAPOSS-co-AA)。采用傅里叶变换红外光谱、X射线衍射和扫描电子显微镜对P(MAPOSS-co-AA)水凝胶的结构和溶胀后的形态进行了表征,并对其溶胀性能、药物缓释性能进行了研究。结果表明,XRD图中MAPOSS峰的消失说明MAPOSS均匀地分散在水凝胶交联网络中;与常规聚丙烯酸(PAA)水凝胶相比,MAPOSS的加入明显降低了其吸水能力,即P(MAPOSS-co-AA)水凝胶在模拟肠液(SIF)中溶胀后的孔径明显小于PAA水凝胶,但其pH敏感性不变,即随着pH值的增加,水凝胶的吸水能力增强,溶胀比增加;同时P(MAPOSS-co-AA)水凝胶作为茶碱的药物缓释体系,明显改善了茶碱在模拟胃液(SGF)和SIF中的释放性能,降低了茶碱在SIF中的释放速率。

A series of pH-sensitive organic-inorganic copolymer hydrogels involving acrylic acid （AA） and methacyphenyl polyhedral oligomeric silsesquioxane as monomers were named as P（MAPOSS-co-AA）. The copolymers were synthesized by free radical solution polymerization using N,N-methylenebisacrylamide （MBA） as cross-linking agents and azodiisobutyronitrile （AIBN） as initiators. The structure and morphology of the hydrogels after swelling were represented through FT-IR, XRD and SEM. The pH-sensitive and drug release behavior of the hydrogels were also investigated. The results of the disappearance of the crystalline peak indicate that MAPOSS is homogeneously dispersed in the crossed linked network of the hydrogels. Furthermore, P（MAPOSS-co-AA） hydrogels show a lower swelling ratio, but still exhibit pH dependence due to the addition of MAPOSS reducing the aperture of the hydrogels. Besides, the drug release behavior of P（MAPOSS-co-AA） hydrogels conducted as a drug delivery system of theophylline is obviously improved in SGF and SIF after the addition of MAPOSS, and the release rate of theophylline in SIF is reduced.