pH-sensitive starch hydrogels via free radical graft copolymerization, synthesis and properties
pH-sensitive starch hydrogels via free radical graft copolymerization, synthesis and properties
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DOI：
10.1016/j.carbpol.2009.02.004
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发表时间：
2009-07
影响因子：
11.2
通讯作者：
M. Saboktakin;A. Maharramov;M. Ramazanov
中科院分区：
文献类型：
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作者：
M. Saboktakin;A. Maharramov;M. Ramazanov
天然聚合物被认为是高价值的聚合物材料，因为它们具有潜在的医疗应用的生物相容性材料。近年来，由于天然聚合物的单体种类繁多，通过接枝对其进行化学改性受到了极大的关注。作为将羧甲基淀粉(CMS)转化为有用的生物聚合物材料的持续研究的第一部分，通过接枝聚甲基丙烯酸(PMAA)在CMS上引入了大量的羧基官能团。以双丙烯酰胺为交联剂，过硫酸盐为引发剂，在70℃进行自由基接枝共聚反应。在无酶模拟胃液和肠液(分别为SGF和SIF)中进行平衡溶胀研究。同时，双芬酸钠作为模型药物被包裹在这些纳米凝胶中，并分别在无酶SGF和SIF中建立了体外释放曲线。SIF的药物释放较快。药物释放曲线表明，药物释放量取决于它们的溶胀程度和交联度。采用冷冻干燥法制备了纳米凝胶，并用扫描电子显微镜、差示扫描量热法和傅立叶变换红外光谱对其进行了表征。
Natural polymers are considered high value polymeric materials because of their potential as biocompatible materials with medical applications. The chemical modification of natural polymers by grafting has received considerable attention in recent years because of the wide variety of monomers available. As the first part of a continued research on conversion of carboxymethyl starch (CMS) to useful biopolymer-based materials, large numbers of carboxylic functional groups were introduced onto CMS by grafting with polymethacrylic acid (PMAA). Free radical graft copolymerization was carried out at 70°C, bis-acrylamide as a crosslinking agent and persulfate as an initiator. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). Also, the sodium dicofenac as a model drug was entrapped in these nano-gels and the in vitro release profiles were established separately in both enzyme-free SGF and SIF. The drug release was found to be faster in SIF. The drug-release profiles indicate that amount drug release depends on their degree of swelling, and crosslinking. This hydrogel converted to nano by freeze-drying method and characterized by scanning electron microscopy, differential scanning calorimetry and FT-IR spectrometry.