Research progress in hydrogel microneedle

Microneedles (MN) as a minimally invasive device consisting of a micro-raised array, can penetrate the cuticle to the epidermis and dermis, and which has the advantages of safety, painless, minimally invasive, self-administration and convenience. As a new kind of microneedles, hydrogel microneedles have attracted more attentions in the medical field due to its excellent performance. Hydrogel microneedles have good biocompatibility and mechanical properties, and can be completely removed after skin action without residual polymer in the body. Its unique swelling property can realize minimally invasive extraction of human detection substance and slow release of drugs, which can play a huge role in the field of personal health monitoring and drug controlled release in the future. The mechanism of action, design, preparation and application of hydrogel microneedles were reviewed in this paper, focusing on the current design parameters of hydrogel microneedles and their applications in drug delivery, extraction monitoring and wound healing, and the problems of hydrogel microneedles in skin infection risk, pharmacokinetics and wearing comfort were pointed out. In the future, the key research direction is to combine with intelligent devices to realize both human body monitoring and intelligent drug controlled release on the microneedle patch.