Advances in Islet Transplantation for Type 1 Diabetes: From Conventional Methods to Stem Cell-Derived Therapies

Aim: This review aims to comprehensively evaluate islet transplantation as a treatment for type 1 diabetes mellitus (T1DM), exploring its mechanisms, clinical applications, current challenges, and future potential. Additionally, we explore the potential of stem cell-derived β-cells and the technologies used to differentiate pluripotent stem cells into insulin-producing cells. Methods: A systematic literature review was conducted using three electronic databases: PubMed, Google Scholar, and Scopus. A total of 71 peer-reviewed articles published between 1979 and 2025 were selected based on keywords such as islet transplantation, pancreatic islet cells, stem cell-derived β-cells, and immunosuppression. The analysis primarily focused on the most recent publications, with additional selection criteria including the number of citations and the sample size of the study population. Results: Islet transplantation is a promising therapy for selected T1DM patients, particularly those experiencing severe glycemic instability. While autologous transplantation following total pancreatectomy effectively preserves endogenous insulin production, allogeneic transplantation remains constrained by donor scarcity and immune-related challenges. The Edmonton protocol has significantly improved graft survival; however, long-term immunosuppression presents considerable risks. Advances in pluripotent stem cell-derived β-cells offer a potential solution to the donor shortage, demonstrating functional insulin secretion in both preclinical and early clinical studies. Alternative transplantation sites, such as the rectus abdominis muscle, have shown promise in enhancing graft viability and function. Conclusions: Islet transplantation, despite its limitations, remains a viable therapeutic strategy for T1DM patients with poor glycemic control. Stem cell-derived islets represent a breakthrough in overcoming donor shortages, yet further large-scale trials are required to validate their efficacy and safety. Continued research on optimizing transplantation techniques and immunosuppressive strategies will be essential for the future of β-cell replacement therapy.