Cell-Based Therapies for Type 1 Diabetes: A Narrative Review of Stem Cell-Derived Islets, Encapsulation Strategies, and Recent Clinical Trials

Type 1 diabetes (T1D) is an autoimmune disease characterized by the destruction of insulin-producing pancreatic β-cells, necessitating lifelong insulin therapy. While islet transplantation has demonstrated efficacy in restoring glycemic control, donor scarcity and the requirement for chronic immunosuppression limit its widespread application. Recent advances in stem cell biology, bioengineering, and immunomodulation have catalyzed a paradigm shift toward stem cell-derived β-cell replacement therapies. This narrative review presents recent clinical trials and technological innovations in cell-based therapies for T1D, with particular emphasis on stem cell-derived islet generation, encapsulation strategies for immunoprotection, and emerging clinical evidence. Landmark clinical trials and pioneering work with chemically induced pluripotent stem cells have demonstrated proof-of-concept for insulin independence and glucose-responsive C-peptide secretion. Encapsulation technologies, ranging from macroencapsulation devices to microencapsulation with bioactive materials, aim to eliminate the need for systemic immunosuppression while protecting grafts from immune rejection. Despite promising early results, challenges including fibrosis, vascularization, long-term graft survival, and scalable manufacturing remain. This review provides a comprehensive overview of the current state of cell-based therapies for T1D and outlines future directions for translating these innovations into routine clinical practice.