Evolving transdermal therapeutics: a review on self-dissolving polymeric microneedles via 3D printing

In recent years, 3D-printed Polymeric Microneedles (PMNs) have been at the forefront of innovations in several biomedical applications, especially in Transdermal drug delivery (TDD) systems. Biocompatible polymers are preferred for their tunable properties that mimic the natural cellular environment, enhancing their clinical suitability. However, their limitations in mechanical strength and stability often require hybridization with synthetic polymers for optimal PMN fabrication. 3D-printed PMNs enable minimally invasive, patient-centric drug delivery, and this review examines diverse microneedle (MN) designs to enhance TDD efficacy, supporting cost-effective clinical translation. This review highlights key aspects like physicochemical properties and their crucial role in additive manufacturing drug delivery systems, which have been underreported. The different sections delve into the challenges of polymeric resin mixes adapted for vat polymerisation and how they can be considered biocompatible, providing detailed insights into the integration potential within future public healthcare frameworks. Furthermore, the review illuminates the clinical outlook, future potential, and strategic directions of PMNs as a pivotal system for TDD, incorporating progress made over the past decade. This review will explore the prospects, benefits, and drawbacks of drug delivery via 3D-printed PMN array, addressing key research gaps essential for advancing the industrialization of this cost-effective drug delivery system.