A New Islet Transplantation Method Combining Mesenchymal Stem Cells with Recombinant Peptide Pieces, Microencapsulated Islets, and Mesh Bags.

Microencapsulated islet transplantation was widely studied as a promising treatment for type 1 diabetes mellitus. However, micro-encapsulated islet transplantation has the following problems-early dysfunction of the islets due to the inflammatory reaction at the transplantation site, and hyponutrition and hypoxia due to a lack of blood vessels around the transplantation site, and difficulty in removal of the islets. On the other hand, we proposed a cell transplantation technique called CellSaic, which was reported to enhance the vascular induction effect of mesenchymal stem cells (MSCs) in CellSaic form, and to enhance the effect of islet transplantation through co-transplantation. Therefore, we performed islet transplantation in diabetic mice by combining three components-microencapsulated islets, MSC-CellSaic, and a mesh bag that encapsulates them and enables their removal. Mesh pockets were implanted in the peritoneal cavity of Balb/c mice as implantation sites. After 4 weeks of implantation, a pocket was opened and transplanted with (1) pancreatic islets, (2) microencapsulated islets, and (3) microencapsulated islets + MSC-CellSaic. Four weeks of observation of blood glucose levels showed that the MSC-CellSaic co-transplant group showed a marked decrease in blood glucose levels, compared to the other groups. A three-component configuration of microcapsules, MSC-CellSaic, and mesh bag was shown to enhance the efficacy of islet transplantation.