Chen Yi, Peng Chang, Lu Yanbing, Liu Wenyong, Xu Weijian
J Nanosci Nanotechnol. 2015 Jan;15(1):164-71. doi: 10.1166/jnn.2015.8768.
PH and temperature double responsive semi-IPN hydrogels consisting of poly(dimethylaminoethyl methacrylate) (PDMAEMA) network crosslinked by nano-sized inorganic clay and linear carboxymethyl chitosan (CMCS) were synthesized by in situ, free radical polymerization in aqueous solution. The effect of the mass and carboxymethyl substitution of CMCS on the responsiveness, swelling/deswelling and drug release characteristic of gels were investigated. Comparing to the gels without CMCS, the resulting gels (named as C-NC gels) showed similar LCST and temperature response behavior. However, with the increase of added CMCS, the swelling ratio of gels decreased considerably around the isoelectric point (IEP) of CMCS, while increased in both strong acidic and alkaline condition. The deswelling rate was improved significantly when the content of CMCS is high. In drug load and release test by using theophylline as target, the C-NC gels exhibited an excellent load ability and controlled-release in simulated human intestinal and stomachic condition. Additionally, all properties of gels were affected by the DS of added CMCS due to the different ratio and interaction of negative and positive ions in gels.
通过在水溶液中进行原位自由基聚合，合成了由纳米级无机粘土交联的聚（甲基丙烯酸二甲氨基乙酯）（PDMAEMA）网络和线性羧甲基壳聚糖（CMCS）组成的pH和温度双响应半互穿网络水凝胶。研究了CMCS的质量和羧甲基取代度对凝胶的响应性、溶胀/消溶胀及药物释放特性的影响。与不含CMCS的凝胶相比，所得凝胶（命名为C-NC凝胶）表现出相似的最低临界溶液温度（LCST）和温度响应行为。然而，随着CMCS添加量的增加，凝胶在CMCS的等电点（IEP）附近的溶胀率显著降低，而在强酸性和碱性条件下均增加。当CMCS含量较高时，消溶胀速率显著提高。以茶碱为靶点进行药物负载和释放测试时，C-NC凝胶在模拟人体肠道和胃部条件下表现出优异的负载能力和控释性能。此外，由于凝胶中正负离子的比例和相互作用不同，添加的CMCS的取代度（DS）影响了凝胶的所有性能。
