Bioabsorbable device to prepare subcutaneous pockets for islet transplantation

Area of Science:

• Biomaterials Science
• Immunology
• Endocrinology

Background:

• Type 1 diabetes treatment requires islet transplantation but faces challenges with graft survival and immunosuppression.
• Subcutaneous islet transplantation is a less invasive alternative, necessitating methods to create immune-tolerant environments.

Purpose of the Study:

• To develop a method for creating subcutaneous immune-tolerant sites for allogeneic islet transplantation without immunosuppression.
• To evaluate the efficacy of gelatin sheets combined with bFGF and sodium hyaluronate for promoting islet graft survival and function.

Main Methods:

• Gelatin sheets were implanted into subcutaneous pockets in diabetic ACI rats.
• A mixture of basic fibroblast growth factor (bFGF) and sodium hyaluronate was injected around the gelatin sheets.
• Allogeneic islets from F344 rats were transplanted into these prepared sites 7 days later.

Main Results:

• Nine out of ten rats achieved long-term normoglycemia without immunosuppressive drugs.
• The gelatin sheets were largely resorbed by 67 days post-implantation.
• The prepared sites supported allogeneic islet graft survival and function.

Conclusions:

• Gelatin sheets and a sodium hyaluronate-bFGF mixture effectively create subcutaneous immune-tolerant sites.
• This approach enables long-term survival of allogeneic islet grafts and blood glucose control in type 1 diabetes models.
• The findings suggest a potential non-immunosuppressive strategy for islet transplantation therapy.