A subcutaneous pancreatic islet transplantation platform using a clinically applicable, biodegradable Vicryl mesh scaffold - an experimental study

Transpl Int. 2020 Jul;33(7):806-818. doi: 10.1111/tri.13607. Epub 2020 Apr 14.

Abstract

Pancreatic islet transplantation into the liver is an effective treatment for type 1 diabetes but has some critical limitations. The subcutaneous site is a potential alternative transplant site, requiring minimally invasive procedures and allowing frequent graft monitoring; however, hypoxia is a major drawback. Our previous study without scaffolding demonstrated post-transplant graft aggregation in the subcutaneous site, which theoretically exacerbates lethal intra-graft hypoxia. In this study, we introduce a clinically applicable subcutaneous islet transplantation platform using a biodegradable Vicryl mesh scaffold to prevent aggregation in a diabetic rat model. Islets were sandwiched between layers of clinically proven Vicryl mesh within thrombin-fibrin gel. In vitro, the mesh prevented islet aggregation and intra-islet hypoxia, which significantly improved islet viability. In vivo rat syngeneic islet transplantations into a prevascularized subcutaneous pocket demonstrated that the mesh significantly enhanced engraftment, as measured by assays for graft survival and function. Histological examination at 6 weeks showed well-vascularized grafts sandwiched in a flat shape between the mesh layers. The biodegradable mesh was fully absorbed by three months, which alleviated chronic foreign body reaction and fibrosis, and supported long-term graft maintenance. This simple graft shape modification approach is an effective and clinically applicable strategy for improved subcutaneous islet transplantation.

Keywords: Vicryl mesh; biodegradable mesh scaffold; hypoxia; oxygenation; pancreatic islet; subcutaneous cell transplantation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose
  • Diabetes Mellitus, Experimental* / surgery
  • Graft Survival
  • Islets of Langerhans Transplantation*
  • Islets of Langerhans*
  • Polyglactin 910
  • Rats
  • Surgical Mesh

Substances

  • Blood Glucose
  • Polyglactin 910