Engineering pancreatic islet-loaded microfibers via pneumatically-controlled microfluidic spinning for the assembly of a microphysiological system.

Microphysiological systems, including organ-on-a-chip systems, can achieve in vitro biomimicry of tissues and organs using microfluidic three-dimensional cell culture devices. These technologies can compensate for the shortcomings of animal models in basic disease research, and can even replace them in some cases. For example, they have demonstrated significant advantages and potential in the evaluation and screening of drugs for diabetes. In this study, we developed an islet microphysiological system based on a fibrous material and microfluidic spinning. This system includes pancreatic islet-loaded microfibers prepared using controllable pneumatic valves combined with microfluidic spinning technology and a microfluidic system comprising microfibers assembled with vascular endothelial cells. The results showed that the prepared microfibers loaded a large number of monodisperse pancreatic islet clusters with good cell activity and function. Microfibers were assembled with vascular endothelial cells in a microfluidic system, providing a 3D environment that mimicked natural blood vessels and supported high-throughput cell loading. Microfibers are vascularized by endothelial cells that grow on their surfaces. The microfluidic system simulated capillary blood flow and nutrient exchange, thereby enhancing the physiological relevance of the model. We evaluated the diabetes treatment drug Glucagon-like peptide-1 (GLP-1) using this system. Immunofluorescence staining, RT-qPCR, and ELISA confirmed the glucose-lowering and cardiovascular protective effects of GLP-1. This islet microphysiological system provides a novel platform for studying diabetes, screening new drugs, and promoting personalized medicine. The ability of this system to simulate physiological conditions through the synergy of biophysical and biochemical factors makes it a powerful tool for biomedical research.