Morphological and functional characterization of a pancreatic β-cell line microencapsulated in sodium cellulose sulfate/poly(diallyldimethylammonium chloride)

Background: Late diabetic complications cannot be prevented totally by current antidiabetic strategies. Therefore, new therapeutic concepts of insulin replacement such as pancreas transplantation are evolving. Due to the shortage of human donor organs, transplantation of microencapsulated xenogeneic pancreatic islet cells has attracted considerable attention. Sodium cellulose sulfate/poly(diallyldimethylammonium chloride) (NaCS/PDADMAC) is a material with favorable biogenic properties that has been used for microencapsulation of various cell types. However, there are no data on the suitability of NaCS/PDADMAC for microencapsulation of pancreatic beta-cells. Materials and methods: Cell growth and viability of NaCS/PDADMAC-microencapsulated HIT-T15 cells, an immortalized hamster pancreatic beta-cell line, were assessed using a dimethylthiazol-diphenyltetrazoliumbromide (MTT)-based cell growth determination kit and apoptosis was detected by antibodies against activated caspase 3. Glucose-dependent insulin secretion was assessed with ELISA and the uptake of glucose was measured using fluorescence-labeled glucose. Results: Statistical analysis revealed no differences in glucose-dependent cell proliferation, insulin secretion and glucose uptake between non-microencapsulated and microencapsulated HIT-T15 cells. Stimulation of HIT-T15 cells with glucose (100 mg/ml) resulted in a biphasic insulin secretion response. Conclusion: Microencapsulation of HIT-T15 cells in NaCS/PDADMAC does not influence cell proliferation, insulin secretion and glucose uptake. Our results indicate that NaCS/PDADMAC is well suited for microencapsulation of pancreatic beta-cells.