pH敏感型海藻酸钙多孔凝胶微球的制备及溶胀性能的研究

Preparation and swelling property of pH-sensitive calcium alginate porous hydrogel microsphere

以海藻酸钠作为基材,制备了一种在pH值为7.4环境下具有敏感性的多孔水凝胶微球。通过正交试验得到了较佳的制备条件为:海藻酸钠溶液浓度为2%(质量分数),氯化钙溶液浓度为3%(质量分数),水浴温度为60℃,保温时间为40min。在此条件下制得的凝胶微球,在pH值为7.4(结肠pH值环境)的磷酸盐缓冲溶液中溶胀30min后,溶胀比可达21.8;而在去离子水(pH值6左右)和pH值1.2(胃液pH值环境)的缓冲溶液中同样时间的溶胀比仅为1.5。通过添加不同类型和浓度的成孔剂,如PEG200、NaCl等,提高了凝胶微球的溶胀响应速率。结果表明,在没有成孔剂存在的条件下,此凝胶微球在pH值为7.4的缓冲溶液中溶胀到最大溶胀比所需时间为30min,而在添加了适量PEG200、NaCl后,均提高了其溶胀响应速率,分别在10、15min即可达到最大溶胀比。

Sodium alginate was used to prepare a kind of porous pH-sensitive hydrogel microsphere.Optimum preparation conditions,2wt% sodium alginate,3wt% calcium chloride,gelling temperature of 60℃ and heat preservation time for 40min,were obtained by orthogonal experiment.The swelling ratio of the gel microsphere was 21.8 in pH 7.4 buffer solution（colon pH value environment）for 30min,while it was only 1.5 in deionized water（pH value 6）or pH 1.2 buffer solution（gastric pH value environment）for the same time.The swelling response rate was increased significantly after adding pore former,such as PEG200 and NaCl.The time to swell to the biggest swelling ratio of the gel microsphere was 30 min without pore former in pH 7.4 buffer solution,while the time was 10 min and 15min respectively with appropriate PEG200 and NaCl.