PH SENSITIVE COMPLEX HYDROGELS AND IPNS FOR DRUG RELEASE

用于药物控制输送的新型载体是由 水凝胶能够对pH，离子强度， 生理溶液的组成和温度。这种水凝胶可以 用于以恒定的速率突然释放药物或蛋白质。我们 建议开发聚乙二醇接枝共聚物 聚甲基丙烯酸，可通过氢键络合。vt.在.的基础上 将药物或蛋白质加载到这些系统中，并在突然变化时 周围溶液的pH值从酸性到碱性是有可能的 使网络解体，导致药物突然释放。另一种选择 基于络合互穿聚合物网络的释药系统 也被开发出来了。PH敏感的聚羟乙基水凝胶 丙烯酸)在一定浓度的水存在下合成 大于相应凝胶的平衡浓度。 当这些系统装载了药物或蛋白质并在体内膨胀时 恒定的pH溶液，它们下沉(坍塌)转化聚合物 系统变成高度渗透性的凝胶。因此，被并入的药物可以 以恒定的速度释放。释放过程取决于pH值 以及溶液的温度。药物释放的实验研究 从这样的系统中会进行整体的放行行为 将由模特领衔。

Novel carriers for controlled delivery of drugs are prepared from hydrogels that have the ability to respond to pH, ionic strength, composition of physiological solution and temperature. Such hydrogels can be used for abrupt release of drugs or proteins at constant rates. We propose to develop graft copolymers of poly(ethylene glycol) with poly(methacrylic acid), which can complex by hydrogen bonding. Upon loading these systems with drugs or proteins and upon abruptly changing the pH of the surrounding solution from acidic to basic it is possible to decomplex the network leading to sudden drug release. An alternative release system based on interpenetrating polymeric networks of complexing is also developed. Finally, pH-sensitive hydrogels of poly(hydroxyethyl acrylic acid) are synthesized in the presence of water at concentrations larger than the equilibrium concentrations of the corresponding gels. When these systems are loaded with drugs or proteins and swollen in constant pH solutions, they deswell (collapse) transforming the polymer system into a highly porous gel. Thus, the incorporated drugs can be released at constant rates. The release process is dependent on the pH and temperature of the solution. Experimental studies of drug release from such systems will be carried out and the overall release behavior will be model led.