Abstract / Summary
Type 1 diabetes mellitus (T1DM) results from autoimmune destruction of pancreatic β cells and requires lifelong insulin replacement. Islet transplantation can restore endogenous insulin secretion, but donor scarcity, immune rejection, early graft loss, inadequate oxygen delivery, and fibrosis limit its application. This review examines conventional and emerging islet tissue-engineering approaches and proposes a conceptual hybrid bio-artificial islet system (HBAIS). A heuristic constraint-exchange framework compares the functions gained from successive technological additions with their associated risks, overlapping benefits, and operational dependencies. The analysis identifies hypoimmune stem cell-derived β cells within a retrievable, transport-permissive interface, supplemented by temporary oxygen generation, as a provisional core configuration. Optogenetic amplification and synthetic protocell-mediated vascular support remain conditional additions when intrinsic insulin responsiveness or host vascular integration is inadequate. The review also proposes auxiliary donor-antigen-matched decoys, including lymph-node grafts, retrievable implants, and intraportal islets, as potential means of relocating immune interactions away from the principal graft. Their ability to intercept immune effectors or promote donor-specific regulation, rather than amplify sensitization, requires experimental evaluation. The framework and integrated system remain unvalidated, but provide a structured basis for investigating β-cell replacement architectures whose added complexity is justified by functional benefit.