Phase-changing antioxidant scaffold shows promise for omentum islet transplantation: A non-human primate case study

Statement of Purpose: Pancreatic islet transplant is a promising clinically-used therapy for type I diabetic and post-total pancreatectomy pancreatitis patients. Islets are transplanted in a minimally invasive procedure via the hepatic portal vein. However, the proinflammatory environment of the liver exposes islets to the instant blood-mediated inflammatory reaction and hypoxic conditions, thus making this transplantation site unideal for engraftment. As a result, islet viability is greatly reduced, and graft failure is commonplace. The omentum provides a viable alternative site for laparoscopic islet transplants. Previous studies have used a biological scaffold made from autologous plasma and thrombin.¹ However, due to the inflammatory nature of a diabetic or pancreatitis patient’s own blood, this approach is unideal. Herein, we describe the use of a thermoresponsive, antioxidant macromolecule poly(polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) to protect islets from inflammatory damage and to create an antioxidative niche for their engraftment in the omentum. Our findings support the use of PPCN for laparoscopic omentum islet transplantation to reduce inflammatory oxidative damage to islet and improve patient outcomes.