Microneedles with Two-Stage Glucose-Sensitive Controlled Release for Long-Term Insulin Delivery

Diabetes patients cannot complete effective blood glucose regulation due to their impaired pancreatic function. At present, subcutaneous insulin injection is the only treatment for patients with type 1 and severe type 2 diabetes. However, long-term subcutaneous injection will cause patients with intense physical pain and lasting psychological burden. In addition, subcutaneous injection will lead to hypoglycemia risk to a large extent because of the uncontrollable release of insulin. In this work, we developed a glucose-sensitive microneedle patch based on phenylboronic acid (PBA)-modified chitosan (CS) particles and poly(vinyl alcohol) (PVA)/poly(vinylpyrrolidone) (PVP) hydrogel for the efficient delivery of insulin. Meanwhile, through the double glucose-sensitive response process of CS-PBA particle and external hydrogel, the sudden release of insulin was well restrained, and a more persistent blood glucose control was achieved. Finally, the painless, minimally invasive, and efficient treatment effect of the glucose-sensitive microneedle patch indicated its great advantages as a new generation of injection therapy.