Abstract:

BACKGROUND: Microencapsulation has been widely used in various experimental studies, microencapsulated stem cell therapy for diabetic mellitus has become a hot issue, but the relationship between the wrapped cell concentration and the insulin release becomes one of the problems required to be solved.
OBJECTIVE: To investigate the influence to the release of insulin and C peptide by the density of the insulin-producing cells (IPCs) encapsulated by alginate-polylysine-alginate microcapsules.
METHODS: The extracts of rat pancreatic injury were prepared, and mouse bone marrow mesenchymal stem cells were induced to differentiate into IPCs. Immunofluorescence and dithizone staining were used to identify the expression of insulin in the induced cells. IPCs were prepared into cell suspension at 1×10⁷/L, 5×10⁴/L, 1×10⁸/L, 5×10⁸/L, 1×10⁹/L, 5×10⁹/L, and then prepared microcapsules by gas blowing spray. Cell viability was detected with 6-carboxyl fluorescein diacetate. Glucose was used to stimulate the cells in microcapsules and to examine the release of insulin and C peptide.
RESULTS AND CONCLUSION: After extracts of rat pancreatic injury were induced, the immunofluorescence and dithizone staining have identified the insulin expression in IPCs; IPCs microcapsule was approximately 400 um diameter with uniform size, 6-carboxyl fluorescein diacetate detected that cell vitality was good. Glucose was used to stimulate the microcapsules at different cell densities, results found that the secretion of insulin and C peptide reach a peak at cell density of 1×10⁸/L.