纤维蛋白原在微胶囊表面的吸附行为  

Adsorption behavior of fibrinogen onto alginate-chitosan-alginate microcapsules

作　　者：谢红国[1,2] 李晓霞[1,2] 林军章[1,2] 谢威扬[1] 马小军[1] 

机构地区：[1]中国科学院大连化学物理研究所生物医用材料工程组,辽宁大连116023 [2]中国科学院研究生院,北京100039

出　　处：《化工学报》2009年第4期929-935,共7页CIESC Journal

基　　金：国家自然科学基金重点项目(20736006);国家高技术研究发展计划重大项目(2006AA02A140)~~

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 micro-encapsulated 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.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.

关 键 词：微胶囊 蛋白吸附 纤维蛋白原 

分 类 号：R318.08[医药卫生—生物医学工程]