From Materials to Intelligent Systems: Cutting-Edge Advances in Microneedle Technology for Drug Delivery and...

Microneedles have achieved remarkable breakthroughs in the fields of transdermal drug delivery and minimally invasive diagnosis and treatment. Over the past decades, it has been remarkably improved by developing delivery and diagnostic strategies based on the microneedle (MN) platform and leveraging its characteristic of minimally invasive penetration through the stratum corneum barrier, the bioavailability of drugs and the accuracy of diagnosis and treatment, achieving efficient local therapy while reducing the systemic side effects of drugs. This article first explains and clarifies the paradigm shift in the evolution of microneedle technology from passive delivery tools to active intelligent systems. Subsequently, it systematically reviews the latest advances in the 4D collaborative design of material composition, geometric structure, payload, and functional intelligence for constructing advanced microneedle systems, including tunable bionic/composite matrices, complex structures enabling spatiotemporally programed drug release, loading of multiscale therapeutic agents, and intelligent functions integrating sensing, response, and feedback control. At the end of the paper, the core implementation obstacles and emerging opportunities faced by this technology in clinical translation and personalized medicine are prospectively discussed.