This islet-on-a-chip platform’s main key feature is extending the cell survival and culture time through minimizing disruption of islet-matrix interactions following isolation. Protocols for decellularized extracellular matrix (ECM) hydrogels were tested and refined with both rodent and human islets. Islets encapsulated in the optimized gels showed enhanced functionality and retention. These supportive 3-D physiomimetic ECM hydrogels can be leveraged within microfluidic platforms for the long-term culture of islets.