Novel microsphere scaffold-based islet organoids for rescuing type 1 diabetes and reversing hyperglycemia

• Three-dimensional porous microsphere scaffolds are constructed based on microfluidic technology to form a multi-stage pore network through controlled stacking to promote cell infiltration and material exchange to support high-throughput organoid culture and physiological microenvironment simulation; their surface biomimetic modification can achieve high biocompatibility. • Primary pancreatic islet cells were successfully induced into highly homogeneous islet-like organs using an inexpensive and rapid culture method; they maintained efficient insulin secretion in vitro and showed significant glucose regulation in a mouse model. • PI3K/Akt pathway play a important regulatory role in the glucose response in organoids, forming a signaling chain that regulates glucose homeostasis by modulating membrane localization ofglucose transporter proteins, insulin secretion,and target cell sensitivity. Type 1 diabetes (T1D) is an autoimmune deficiency disease characterized by elevated blood sugar levels and insulin resistance, leading to various adverse health effects and complications, such as diabetic cardiomyopathy and diabetic ketoacidosis. Currently, T1D is primarily treated through organoid transplantation and extracorporeal insulin injection. However, the clinical utility of these treatments is limited by increased systemic immunosuppression due to graft donor shortages and the side effects associated with exogenous insulin therapy. Recently, the emergence of bioengineered islet-like organs has opened up possibilities for constructing insulin-secreting cells in vitro to treat insulin-dependent diabetes. In this study, we developed a novel microsphere scaffold-based islet cell spheroid culture system that integrates islet organoids with 3D microsphere scaffolds, enabling the consistent generation of 3D islet cell spheroids. Following transplantation into the renal capsule of diabetic mice, these organoids demonstrated significant hypoglycemic effects, with detectable insulin secretion in the serum. On day 30 post-transplantation, β-cell marker expression was significantly increased in the grafts. We further investigated the glucose-related proteins that microsphere scaffold-based islet organoids may regulate. Our findings confirm that islet-like organoids can effectively secrete insulin and play a role in maintaining blood sugar stability. These results indicate that islet-like organs generated via microsphere scaffolds exhibit similar endocrine functions to those of natural islets, can survive in the host body for extended periods, and can effectively exert hypoglycemic effects, thereby providing a solid foundation for the application of islet-like organs in type 1 diabetes research. Culture and application of islet-like organoids based on hydrogel microsphere scaffolds. A three-dimensional scaffold with a microsphere structure was prepared by using a single milk microfluidic device. Islet fragments containing stem cells were placed on a microsphere scaffold to construct an islet-like organoid culture platform, which was applied to diabetes mellitus, and the function of blood sugar regulation was studied.