Developing ECM Based Platform for Rat Pancreatic Islets Microencapsulation

Background: Pancreatic islets microencapsulation has been studied for treating type 1 diabetes, thus helping the islets cope with the post-isolation and post-transplantation conditions, and provide them with a protective niche. The use of porcine pancreas tissue-derived extracellular matrix (ppECM) for such microencapsulation can offer structural support as well as biological and mechanical cues to the encapsulated cells. Furthermore, encapsulation of islets with mesenchymal stem cells (MSC) had been suggested to improve graft efficacy due to their immunomodulatory properties. Therefore, the goal of this research is to design a platform for the microencapsulation of rat pancreatic islets, which supports and improves their function through the use of natural ppECM and their co-encapsulation with MSC.

Methods: The isolation process of rat islets was optimized through altering the parameters of each step. Porcine pancreatic ECM was decellularized and enzymatically solubilized to produce a thermally induced ppECM hydrogel. This hydrogel was further applied to entrap rat islets within ECM spherical microcapsules using electrospray technology. Islets viability was evaluated using FDA/PI and DAPI/PI staining and insulin production and secretion was measured insulin staining and glucose stimulated insulin secretion.

Results: Rat islets were successfully isolated and encapsulated within ECM microcapsules. Following encapsulation, the islets remained viable for 14 days, thus expressing insulin and glucagon. Furthermore, insulin secretion was shown to be glucose-responsive, indicating at their proper function.

Conclusion: ECM-based microencapsulation supports pancreatic rat islets and enables their long-term survival and function, thus indicating at the potential of this promising platform as a prospective treatment for diabetes.