Objective: To study the effect of alginate purity on microencapsule overgrowth, histology and function of microencapsulated hepatocyte (MH).
Methods: Alginate was purified by filtration and chloroform/butanol extraction. Using purified and crude alginate to make two kinds of MHs, we transplanted each kind of MHs into the peritoneal cavities of rats. After 2 weeks, 1, 2 and 6 months, MHs were washed out to study overgrowth of MH, histology, and expression of enzyme and albumin in hepatocytes. Two kinds of MHs (the purified and the crude) were transplanted to FHF rats separately to study their differences in liver function support.
Results: The amount of retrieved MHs was larger in the purified than in the crude (P < 0.001). In the purified group, most hepatocytes had normal morphology, positive enzymatic histochemistry and albumin immuno-histochemistry stain in one month of transplantation but were damaged in the crude group only 2 weeks later. Microencapsules were smooth and no overgrowth was observed during 6 months in the purified but all overgrowth one month later after transplantation in the crude. The purified MHs had excellent liver function support in the FHF comparing with the crude and the control.
Conclusion: The purified alginate may significantly reduce the overgrowth of MHs and improve the function of hepatocytes.