Preparation of chitosan microspheres for the medical application

本研究制备了多孔颗粒和胶囊，用于修复受损的人体组织。壳聚糖和γ-缩水甘油氧基丙基三甲氧基硅烷（GPTMS）被用作起始原料。将含CaCl_2和不含CaCl_2的前驱体溶胶滴加到液氮中制备多孔粒子。制得的多孔颗粒直径约为2 mm，孔径为10-30μm。在0.01M的Na_2HPO_4溶液中，80℃浸泡7天，可使HAp颗粒在孔表面沉积，粒径约为1μm。牛血清白蛋白（BSA）在壳聚糖-GPTMS颗粒上吸附量较大。通过将羧甲基纤维素滴入壳聚糖-GPTMS溶胶中制备胶囊。胶囊中生物活性分子的释放受交联度的控制。此外，胶囊未显示出细胞毒性。

In this study, Porous particles and capsules were prepared to recover of the damaged human tissues. Chitosan and γ-glycidoxypropyltrymethoxysilane (GPTMS) were used as the starting materials. Porous particles were prepared by dropping precursor sol with CaCl_2 or without into liquid nitrogen. Obtained porous particles had about 2 mm in diameter and 10-30μm in pore size. HAp particles of about 1μm in diameter deposited on the pore surface by soaking thus obtained hybrid parties in 0.01 M Na2HPO4 solution at 80℃ for 7 days. Bovine serum albumin (BSA) adsorbed much on the chitosan-GPTMS particles. Capsules were prepared by dropping carboxymethylcellulose into chitosan-GPTMS sols. The releasing of bioactive molecules included into the capsules was controlled by the cross-linking degree. Moreover the capsules did not show the cytotoxicity.