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Molecular design of graft-type poly (N-isopropylacrylamide) gels containing rapid thermo-response

快速热响应接枝型聚（N-异丙基丙烯酰胺）凝胶的分子设计

基本信息

批准号：
08455458
负责人：
OKANO Teruo
金额：
$ 4.1万
依托单位：
Tokyo Women's Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

Conventional drug release regulation using hydrogels was depended on drug diffusive transport in the gels. In contrast, we investigated a novel thermo-responsive drug release regulation synchronized with convectional water outflow induced by aggregation of network containing comb-type graft chains. Deswelling kinetics of conventional gel without graft chains becomes slow : size-depended kinetics is obtained. This is because swelling to deswelling changes of the conventional gel is governed by collective diffusion of network. In contract, poly(N-isopropylacrylamide) (PIPAAm) network containing comb-type PIPAAm grafts with freely mobile ends shows rapid deswelling changes in response to stepwise temperature changes above 32ﾟC.The graft chains undergo rapid dehydration with temperature changes, accelerating the deswelling changes of the graft-type gel due to strong hydrophobic interaction between dehydrated graft chains. Difference is apparent in drug release pattern from the conventional gel and the graft-type gel. Upon increasing temperature, the conventional gel stops the drug diffusion due to formation of skin layers at the gel surface. In contract, pulsed drug release is achieved synchronized with the convectional water release during the rapid deswelling of the graft-type gel. Details are studies for a new function of thermo-responsive graft-type gel as a micro-pumping matrix.

传统的水凝胶药物释放调节依赖于药物在凝胶中的扩散转运。与此相反，我们研究了一种新的温度响应性药物释放调节与对流水流出诱导的梳型接枝链的网络聚集同步。没有接枝链的常规凝胶的去溶胀动力学变得缓慢：获得尺寸依赖性动力学。这是因为常规凝胶的溶胀到去溶胀的变化由网络的集体扩散控制。相反，含有梳型PIPAAm接枝物的聚（N-异丙基丙烯酰胺）（PIPAAm）网络具有自由移动的末端，显示出响应于高于32 ℃的逐步温度变化的快速消溶胀变化。接枝链随着温度变化而快速脱水，由于脱水接枝链之间的强疏水相互作用，加速了接枝型凝胶的消溶胀变化。与常规凝胶和接枝型凝胶的药物释放模式明显不同。在升高温度时，常规凝胶由于在凝胶表面形成皮层而停止药物扩散。相反，在接枝型凝胶的快速去溶胀期间，实现了与对流水释放同步的脉冲药物释放。详细研究了温敏接枝型凝胶作为微泵基质的新功能。