Biocompatibility of phosphorylcholine modified alginate-chitosan microcapsules / 中华内分泌外科杂志

ABSTRACT

ObjectiveTo explore whether the biocompatibility of phosphorylcholine (PC) modified alginate-chitosan microcapsules could be improved. MethodsPC modified alginate-chitosan microcapsules were obtained by high-voltage electrostatic system.Bradford method was adopted to determine the adsorption amounts of bovine serum albumin by chitosan alone and PC modified chitosan.Alginate-chitosan-PC microcapsules (experimental group) and alginate-chitosan microcapsules ( control group) were respectively implanted into the peritoneal cavity of mice and retrieved 4 weeks after transplantation.Fibrosis of the capsules was evaluated by HE staining.Glucose stimulated insulin secretion (GSIS) assay was used to assess the insulin secretion response of encapsulated and nonencapsulated rat islets. Results The adsorption amount of protein was 189.4 μg/mg and 90.5 μg/mg respectively by chitosan alone and PC modified chitosan.The difference had statistical significance ( t =5.549, P ＜ 0.05 ).In contrast to the control group, the cellular reaction on the surface of the modified microcapsules was weaker, with no obvious fibrosis found.The insulin secreted by encapsulated islets and nonencapsulated islets was( 3.298 ± 1.680 ) μIU/ml VS (4.299 ± 1.159 ) μIU/ml ( t =1.096, P ＞ 0.05 ) in response to low-glucose stimulus and( 11.783 ± 4.175 ) μIU/ml VS ( 12.875 ± 2.268 ) μIU/ml ( t =0.514, P ＞ 0.05 ) in response to high-glucose stimulus.Conclusions PC can improve the biocompatibility of alginate-chitosan microcapsules, with no effect on the biological function of encapsulated islets.It may be more appropriate to use modified microcapsules encapsulating islets for transplantation.