Effect of molecular weight of chitosan on microcapsules and hypatocytes in microcapsules

Objective To study the influence of molecular weight of chitosan on microcapsules and hepatocytes in microcapsules. Methods The mechanical strength, permeability to fluoresceine isothiocyanate-bovine serum albumin (FITC-BSA) and activity of hepatocytes in microcapsules were compared between two kinds of microcapsules made by low and middle molecular weight chitosan. Results After 100 min of stirring microcapsules, all middle molecular weight chitosan microcapsules were damaged, 5% low molecular weight chitosan microcapsules were damaged. There was significant difference in breakage rate of the mechanical strength between two microcapsules (P ＜ 0. 05). Fifteen min after addition of FITCBSA into microcapsule solution, fluorescence intensity in the low molecular weight chitosan microcapsules was 4 AU, and that in middle molecular weight of chitosan microcapsules was 1. 5 AU, suggesting there was significant difference in permeability to FITC-BSA between two kinds of microcapsules (P ＜ 0. 05).One week after culture of microencapsulated hepatocytes, staining test showed that 100% of liver cells in low molecular weight chitosan microcapsules were alive, while the number was about 40% in middle molecular weight chitosan microcapsules (P ＜ 0. 05). Conclusion Low molecular weight chitosan is more suitable as materials of microcapsules than molecular weight chitosan. Key words: Hepatocyte; Microcapsules; Chitosan