Chemical and Pharmaceutical Engineering Institute, Hebei University of Science and Technology, Hebei 050018, China.
J Biomater Sci Polym Ed. 2013;24(12):1459-71. doi: 10.1080/09205063.2013.768943. Epub 2013 Feb 26.
The main aim of the present study was to develop a series of pH-sensitive hydrogels for targeted releasing drugs under simulated intestinal environment instead of stomach condition. These hydrogels were prepared via free radical polymerization with polyethylene glycol methacrylate 475 (PEGMA475), PEGMA950 and methacrylic acid as monomers, triethylene glycol dimethacrylate (TRGDMA), and ethylene glycol dimethacrylate as cross-link agents. The surface morphology and internal structures of hydrogels were detected by scanning electron microscope. The swelling experiments were also performed and the results revealed that the smart hydrogels were pH sensitive and their sensitiveness was reversible. Diclofenac sodium and bull serum albumin used as model drugs were loaded in the hydrogels to target releasing them in simulative intestinal tract. In vitro releasing studies showed that medicated hydrogels released model drugs slowly in acid conditions (pH 1.2), while the cumulated release amounts of drugs increased greatly when ambient pH value increased to 7.4. These phenomena indicated that these hydrogels tended to target release stimulating and destructible drugs in intestinal canal instead of gastric environment.
本研究的主要目的是开发一系列在模拟肠道环境下靶向释放药物的 pH 敏感水凝胶，而不是在胃条件下。这些水凝胶是通过自由基聚合以聚乙二醇甲基丙烯酸酯 475（PEGMA475）、PEGMA950 和甲基丙烯酸为单体，三甘醇二甲基丙烯酸酯（TRGDMA）和乙二醇二甲基丙烯酸酯为交联剂制备的。通过扫描电子显微镜检测了水凝胶的表面形态和内部结构。还进行了溶胀实验，结果表明智能水凝胶具有 pH 敏感性，其敏感性是可逆的。将双氯芬酸钠和牛血清白蛋白用作模型药物载入水凝胶中，以在模拟肠道中靶向释放它们。体外释放研究表明，在酸性条件（pH 1.2）下，载药水凝胶缓慢释放模型药物，而当环境 pH 值升高到 7.4 时，药物的累积释放量大大增加。这些现象表明，这些水凝胶倾向于在肠道中靶向释放刺激性和破坏性药物，而不是在胃环境中。
