Microneedles in Smart Drug Delivery.

Significance In biomedical setup, at large, and drug delivery, in particular, transdermal patches, hypodermal needles and/or dermatological creams with the topical appliance are among the most widely practiced routes for transdermal drug delivery. Owing to the stratum corneum layer of the skin, traditional drug delivery methods are inefficient, and the effect of the administered therapeutic cues is limited. Recent Advances The current advancement at the micro- and nano- level has revolutionized the drug delivery sector. Particularly, various types of microneedles are becoming popular for drug delivery applications because of safety, patient compliance, and smart action. Critical Issues Herein, we reviewed state-of-the-art microneedles as a smart and sophisticated drug delivery approach. Following a brief introduction, the drug delivery mechanism of microneedles is discussed. Different types of microneedles, i.e., solid, hollow, coated, dissolving, and hydrogel-forming microneedles, are discussed with suitable examples. The latter half of the work is focused on the applied perspective and clinical translation of microneedles. Furthermore, a detailed overview of clinical applications and future perspectives are also included in this review. Future Directions Regardless of ongoing technological and clinical advancement, the focus should be diverted to enhance the efficacy and strength of microneedles. Besides, the possible immune response or interference should also be avoided for successful clinical translation of microneedles as an efficient drug delivery system.