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Updated: Jun 22, 2026
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Scaffold-supported Transplantation of Islets in the Epididymal Fat Pad of Diabetic Mice
Published on: July 23, 2017
Enhancement of Subcutaneous Islet Transplant Performance by Collagen 1 Gel
Anna French1,2, Jennifer Hollister-Lock1,2, Brooke A Sullivan1,2
1Harvard Medical School, Joslin Diabetes Center, Boston, MA, USA.
Cell Transplantation
|October 3, 2024
Summary
Transplanting islets within a collagen gel disk significantly improves survival and function at the subcutaneous site. This method effectively reverses diabetes, offering a promising alternative transplant strategy for type 1 diabetes.
Area of Science:
- Endocrinology
- Regenerative Medicine
- Transplantation Biology
Background:
- Type 1 diabetes management often involves islet transplantation, with the portal vein as a common site.
- The subcutaneous (SC) site is explored as an alternative but faces challenges in islet survival and function.
- Improvements in vascularization and differentiation factors, including collagen, have been investigated for SC transplants.
Purpose of the Study:
- To evaluate the efficacy of transplanting rat islets within a type 1 collagen gel disk at the SC site.
- To compare the survival and function of islets in collagen disks with those transplanted in ungelled collagen or other sites.
- To assess the potential of this method for reversing diabetes in a preclinical model.
Main Methods:
- Rat islets were encapsulated in type 1 collagen gel disks before SC transplantation.
- Islet survival was assessed by comparing insulin content post-transplantation to pre-transplantation levels.
- Diabetes reversal in NOD scid IL2R gamma null (NSG) mice with streptozotocin (STZ)-induced diabetes was monitored.
- Vascularization was evaluated using whole mount imaging.
Main Results:
- Islet grafts in collagen disks showed more than double the recovered insulin compared to islets in ungelled collagen at 14 days post-transplantation.
- SC grafts of collagen disks demonstrated comparable insulin content to kidney and epididymal fat pad grafts.
- Despite disk contraction, islets remained healthy, and vascularization was supported by host blood vessel ingrowth.
- Transplantation of 400 rat islet equivalents (IEQ) in collagen disks into the SC site effectively reversed STZ-induced diabetes within 10 days, similar to kidney site transplants.
Conclusions:
- Encapsulating islets in type 1 collagen gel disks enhances their survival and function at the SC transplant site.
- This simple modification improves SC islet transplantation outcomes, achieving prompt diabetes reversal.
- Collagen gel disks represent a viable strategy to improve islet transplantation efficacy at alternative sites.
