A silk-based encapsulation platform for pancreatic islet transplantation improves islet function in vivo

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Transplantation Immunology

Background:

• Pancreatic islet (PI) transplantation is crucial for diabetes treatment but faces challenges due to peritransplantation damage.
• Mesenchymal stromal cells (MSCs) show immunomodulatory potential, but their integration with PI grafts needs optimization.

Purpose of the Study:

• To evaluate a silk-based encapsulation platform for delivering PI grafts in vivo.
• To assess the impact of co-encapsulating PI with MSCs within silk on graft function and immune response.

Main Methods:

• Islet equivalents (IEQs) were transplanted into diabetic mice using three methods: PI with MSCs in silk, PI in silk alone, or pelleted PI.
• Blood glucose levels and intraperitoneal glucose tolerance tests (IPGTT) were monitored.
• Graft histology and cytokine analysis were performed.

Main Results:

• Silk-encapsulated PI grafts, especially those with MSCs, rapidly restored euglycemia.
• PI co-encapsulated with MSCs in silk showed significantly improved IPGTT compared to other groups.
• While silk grafts increased Th1/Th2 cytokines, co-encapsulation with MSCs significantly reduced Th1 cytokines. Osteogenesis and chondrogenesis were observed in MSC-containing silk grafts.

Conclusions:

• Silk-based encapsulation, particularly with MSCs, offers a promising strategy to improve PI transplantation efficacy.
• This approach mitigates immune responses and enhances graft function, potentially overcoming a key barrier in diabetes treatment.
• Further research is needed to optimize MSC stability and silk material properties for clinical application.