Hydrogel materials for the application of islet transplantation

Type 1 diabetes mellitus is a serious disease comprising approximately 10% of all diabetes cases, and the global incidence of type 1 diabetes mellitus is steadily rising without any promise of a cure in the near future. Although islet transplantation has proven to be an effective means of treating type 1 diabetes mellitus and promoting insulin independence in patients, its widespread implementation has been severely constrained by instances of post-transplantation islet cell death, rejection, and severe adverse immune responses. Islet encapsulation is an active area of research aimed at shielding implanted islets from immunological rejection and inflammation while still allowing for effective insulin and nutrient exchange with donor cells. Given their promising physical and chemical properties, hydrogels have been a major subject of focus in the field of islet transplantation and encapsulation technology, offering promising advances towards immunologically privileged islet implants. The present review therefore summarizes the current state of research regarding the use of hydrogels in the context of islet transplantation, including both natural molecular hydrogels and artificial polymer hydrogels, with the goal of understanding the current strengths and weaknesses of this treatment strategy.