Multifunctional structural color triboelectric microneedle patches for psoriasis treatment

Microneedles have demonstrated an essential role in transdermal drug delivery strategy. Attempts to advance this technology focus on the improvement of functionality to realize controllable drug release with a self-reporting capability. Here, we present multifunctional structural color triboelectric microneedle (MN) patches with the desired features for treating psoriasis. Such MN patches are made of a budesonide-encapsulated polyacrylamide-poly(ethylene glycol) diacrylate-lithium chloride (PAM-PEGDA-LiCl) ionic hydrogel, which possesses inverse opal scaffold structures. The resultant MN patches are not only forced to release drugs but also contribute to reducing the degree of skin fibrosis with their mechanical behavior, thereby promoting the treatment of psoriasis. Notably, these MN patches exhibit vivid structural color, imparting them with self-reporting capability, which can be applied for visually monitoring the performance of drug release during in vivo treatment of psoriasis mice. We believe that the proposed MN patches would be valuable in practical applications.