Microneedles combined with a sticky and heatable hydrogel for local painless anesthesia.

In view of the inherent defects of traditional syringe anesthesia (pain, inaccurate anesthesia area, swelling after injection, slow recovery etc.), this article proposed a new anesthesia system based on microneedles and a hydrogel. After loading with AuNPs, a sticky PDA-PAM-AuNP hydrogel with near-infrared (NIR) light response properties was prepared here. After using microneedles (to open the skin of the target anesthesia area), a hydrogel patch embedded with a medical anesthetic soaked sponge was pasted to realize local painless anesthesia. The effects of anesthesia can also be modulated by external NIR. Compared to traditional syringe anesthesia, this hydrogel + microneedle method resulted in reduced pain, higher anesthetic accuracy and faster recovery, making it a promising local anesthesia alternative in clinical applications.