205-LB: Clinical Validation of the Implanted Prevascularized Cell Pouch as a Viable, Safe Site for Diabetes Cell Therapy

We report current clinical findings for the Cell Pouch (CP), as an implantable and retrievable medical device designed to develop a healthy vascularized tissue environment for transplantation and engraftment of therapeutic cells, which release the desired hormones for the treatment of diabetes, and other diseases. Patients with diabetes were implanted with the CP between 1-6 months, and under immunosuppression transplanted with islets isolated from donor pancreata. CPs (N=9) were explanted (between 14 -90 days post-tx). Histological sections of the explanted CPs were prepared, stained, and then reviewed by an independent pathologist for vascularization, and the presence of islets with insulin, C-peptide, and other endocrine hormones (glucagon, somatostatin) and ductal tissue (exocrine tissue) [(+) present; (++) abundant marked clusters of cells; (-) absence]. Pathology analysis revealed that 100% of the CPs were well-vascularized within a rich tissue bed. Of the CPs assessed, 89% (+ or ++) showed insulin; 78% (+ or ++) showed endocrine cells; 100% (+ or ++) showed ductal tissue. Islets were intimately related to micro-vessels in the CP tissue matrix. The amount of islets/exocrine tissue within the pre-transplant samples was similar to that found within the CPs that were explanted. With these findings, we have clinically demonstrated the vascularized Cell Pouch provides a safe and suitable, retrievable environment for the transplantation and survival of functional islets. With new emerging cellular replacement therapies as a clinical solution for all patients with diabetes, the unique Cell Pouch system solves a need to support a successful, positive clinical transplant outcome.