Correction of Hyperglycemia in Diabetic Rats With the Use of Microencapsulated Young Market Pig Islets.

OBJECTIVE: The aim of this work was to investigate the transplantation efficacy of microencapsulated young market pig islets in a diabetic rat model. METHODS: Islets were isolated and purified from young market pigs obtained from a local slaughterhouse. The islets were encapsulated in barium alginate and subjected to a glucose-induced insulin release functional assay in culture. Microencapsulated islets were transplanted into diabetic Sprague-Dawley rats and removed after 30 days for histologic examination. RESULTS: The mean islet equivalent (IEQ) yield per gram of digested tissue was 3,125 ± 617 IEQ/g after isolation and 2,618 ± 917 IEQ/g after purification, respectively. Host rats' blood glucose concentrations normalized (from 22.3 ± 2.7 mmol/L to 5.1 ± 0.67 mmol/L) following encapsulated islet transplantation. After graft removal, hyperglycemia recurred in the rats, indicating that the grafts were responsible for maintaining euglycemia. Histology revealed viable islets in the capsules 30 days after graft removal. Immunolabeling of insulin verified that ß-cells within the capsules remained well granulated. No fibrosis or immune cells were found in histopathology. CONCLUSIONS: Barium alginate encapsulation of young market pig islets can normalize glucose regulation in diabetic rats without fibrosis or an immunologic response.