Insulin and glucagon secreted from the pancreas with dynamic balance play a vital role in regulating blood glucose levels. Although distinct glucose-responsive insulin delivery systems have been developed, the lack of a self-regulated glucagon release module limits their clinical applications due to the potential risk of hypoglycemia. Here, we describe a transdermal polymeric microneedle patch for glucose-responsive closed-loop insulin and glucagon delivery to achieve glycemic regulation with minimized risk of hypoglycemia. The glucose-responsive phenylboronic acid units can bind to glucose to reversibly shift the net charge (from positive to negative) of the entire polymeric matrix within microneedles. Therefore, the release ratio of the negatively charged insulin and the positively charged glucagon analog from the patch can be dynamically tuned upon the fluctuation of blood glucose levels to realize glycemic homeostasis. In both chemically induced type 1 diabetic mouse and minipig models, this glucose-responsive dual-hormone microneedle patch demonstrated tight long-term regulation in blood glucose levels (>24 hours in minipigs).

Timely administration of emergency therapeutics is critical for patients with sudden-onset illnesses. In article number 2208648, Haojian Lu, Jicheng Yu, Zhen Gu, and co-workers develop an unmanned aerial vehicle (UAV)-mediated first-aid system (uFAST), which enables the autonomous administration of emergency therapeutics via a UAV without the involvement of an additional or conscious person to achieve timely first aid.

Timely administration of key medications toward patients with sudden diseases is critical to saving lives. However, slow transport of first‐aid therapeutics and the potential absence of trained people for drug usage can lead to severe injuries or even death. Herein, an unmanned aerial vehicle (UAV)‐mediated first‐aid system for targeted delivery (uFAST) is developed. It allows unattended administration of emergency therapeutics‐loaded transdermal microneedle (MN) patches toward patients to relieve symptoms by a contact‐triggered microneedle applicator (CTMA). The implementability and safety of the uFAST for first aid is demonstrated in a severe hypoglycemic pig model by automatically delivering a glucagon patch with immediate and bioresponsive dual release modes. This platform technique may facilitate the development of UAV‐mediated first‐aid treatments for other sudden diseases.