中文摘要：

引言 由聚阴离子、聚阳离子经复凝聚反应而制成的粒径约5～1000μm的具有核壳结构的微胶囊，因能凭借其囊膜对囊内包裹的细胞或组织免疫保护而广泛用于细胞或组织移植研究^[1]。目前，线性阴离子天然多糖海藻酸钠（简写为NaAlg或Alg，由α-L-甘露糖醛酸与β-D-古罗糖醛酸依靠1，4-糖苷键连接而成的共聚物）仍是最常用的微胶囊制备聚阴离子材料。

英文摘要：

Alginate-chitosan-alginate （ACA） microcapsules have been widely studied as devices for the immuno-isolation and transplantation of living cells. However, long-term survival of the microencapsulated cell grafts and thus their potential clinical applications are hampered by the pericapsular fibrotic overgrowth induced by adsorbed protein. In this study, the adsorption behavior of plasma fibrinogen （Fgn） onto ACA microcapsules was studied by using the batch technique. The results showed that the equilibrium time for the adsorption was 24 h. The adsorption of Fgn onto ACA microcapsules fitted very well with Freundlich isotherm, which was indicative of multilayer adsorption. The kinetic experimental data correlated well with the second-order kinetic model, indicating that chemical sorption was the rate-limiting step. The effects of pH and ionic strength on the adsorption were also studied to interpret the mechanism of adsorption. It was found that the amount of adsorbed Fgn decreased with increasing pH in the range of 4.9--7.4. At pH 7.4, the amount of adsorbed Fgn increased with increasing NaCl concentration, and then decreased with further increase in NaCl concentration. At pH 6.0, the amount of adsorbed Fgn decreased with increasing NaCl concentration, indicating that electrostatic interaction was one of the main interactions between Fgn and ACA microcapsules and the positively charged chitosans which was not sufficiently neutralized on the surface of microcapsules induced the adsorption.