Improvement of islet transplantation in prevascularized muscle sinus tracts.

This study aimed to develop an optimal alternative site for islet transplantation, addressing the limitations of the current clinical standard, the intrahepatic site. In this study, prevascularized muscle sinus tracts (MSTs) in mice were created by implanting and then removing polyamide rods, leveraging a controlled foreign body reaction to generate a highly vascularized, porous collagen matrix. Transplantation of 350 syngeneic islets into these MSTs consistently reversed diabetes in mice, achieving long-term normoglycemia for over 180 days, with efficacy comparable with kidney capsule transplantation. The approach also supported the survival of human islets in immunodeficient mice and demonstrated feasibility in a porcine autotransplantation model. This work establishes the MST as a simple, effective, and clinically promising strategy that enhances islet engraftment through localized prevascularization, potentially improving the therapeutic outcomes of islet transplantation.