Fabrication of porous polymeric microneedles: a concise overview

Recent advancements in microneedle (MN) technology have increasingly focused on porous polymeric microneedles (PPMNs), which are, among various types of MN, emerging as a promising platform for diverse biomedical applications, including transdermal drug delivery, interstitial fluid (ISF) extraction, and biosensing. This growing interest stems from their distinctive internal architecture, characterized by continuous nano- or micro-scale pores that enable the efficient transport of drugs and biofluids, primarily through capillary action. The optimal selection of polymeric materials, combined with appropriate fabrication techniques, plays a critical role in enhancing the functional performance of PPMNs while ensuring sufficient mechanical strength. This concise review summarizes recent research progress in the fabrication methods of PPMNs, emphasizing the interplay between polymer(s) choice, manufacturing technique, intended biomedical application, and the resulting structural and functional properties of the microneedles. It also addresses key challenges in the fabrication field and discusses future development.