NIPAAm系互穿网络凝胶的合成及载药释药性能研究

合成了三种亲疏水性不同的温度及pH敏感的PAAc／P（NIPAAm-co-BMA）、PAAc／PNIPAAm和PAAc／P（NIPAAm-co-AAm）互穿网络（IPN）水凝胶，以水杨酸钠和水杨酸为模型药物，研究了温度、pH值及药物和凝胶的亲疏水性相互作用对模型药物释药性能的影响。研究结果表明，随着凝胶亲水性的增强，水杨酸钠的载药率提高，释药率也越大；相反疏水性增强也有利于提高水杨酸的载药率；IPN凝胶在水中的释药过程属于溶胀支配型释放，药物释放率随凝胶的亲水性增强而增强，同时，载药凝胶在45℃水中的释药率大于25℃时的释药率。在25℃时，水杨酸在pH=2．2的缓冲溶液中几乎不释放，而在pH=7．4的缓冲溶液中能以较快的速率释放。

Synthesis of IPN Hydrogels Based on N-Isopropylacrylamide and Its Drug Loading and Unloading Property

Three kinds of temperature and pH sensitive interpenetrating networks hydrogels,PAAc/P(NIPAAm-co-BMA),PAAc/PNIPAAm and PAAc/P(NIPAAm-co-AAm),with different hydrophilicity were prepared.With sodium salicylate and salicylic acid as model drug,the influence of temperature,pH and hydrophilicity/hydrophobicity of hydrogel to the loading and release ratio of model drug was studied.The results showed that incorporation of hydrophobic BMA polymer into PAAc/PNIPAAm would increase the loading efficiency of salicylic acid while the hydrophilic AAm would increase loading efficiency of sodium salicylate.The drug delivery system belongs to swelling-dependence.The more the hydrophilic of a gel,the more the release ratio.The releasing ratio of the drug-loaded IPN gels at 45℃ was higher than that at 25℃.Also pH values had a great impact on the release ratio;salicylic acid was almost not released at pH= 2.2 whereas released faster at pH=7.4.