Engineering strategies of islet products for endocrine regeneration

Islet transplant has proven to be one promising strategy for diabetes treatment with minimal invasiveness, which restore the patient's endocrine function and avoid exogenous insulin injection. In the past decades, the ever-increasing diabetic population has brought more demand for this technology, therefore, accelerating the development of numerous engineering technologies optimizing the transplantation efficiency. In this review, we summarized the emerging engineering approaches in this field, aiming to provide a general understanding of islet transplantation challenges and the cutting edge of engineering technologies. Firstly, we introduced the islet product sources used for transplantation and analyzed their respective advantages and disadvantages. Afterwards, we focused on the advanced engineering strategies for maintaining islet graft viability and function in the transplantation. Finally, we summarized the engineering challenges and potential research directions in this field.