in: Microneedles (MNs)-Based Technology, Neetu Talreja,Divya Chauhan,Mohammad Ashfaq, Editor, Springer-Verlag Singapore Pte Ltd, Singapore, pp.87-116, 2025
Microneedles (MNs) are a drug delivery system that is painless, minimally invasive, and with a high drug bioavailability. Hydrogel-based microneedles allow the drug to be delivered slowly because the drug is present in all areas of the microneedle. Drug delivery using hydrogel MNs is safe and non-toxic because of their high drug-loading capacity, regulated drug release, and lack of leftover matrix material. Several beneficial characteristics result from the combination of hydrogels and MNs, including localised, regulated, and prolonged drug release. The synergistic interaction of numerous bioactive components inside the formulation is made possible by this combination, which enhances the efficacy of treatment. Medication delivery systems can benefit from the long-term and multiple medication delivery that hydrogel MNs enable. All things considered, hydrogel MNs present a viable platform for obtaining accurate and customised medication delivery with improved therapeutic results. A viable substitute is offered by 3D printing, which makes it possible to fabricate MN with the high dimensional accuracy required for exact applications. Rapid customisation of MNs is made possible by its one-step procedure and customizability, which presents a favourable growth opportunity, especially for personalised and on-demand medical products. DLP-based printing provides several benefits for applications related to tissue engineering. UV light is projected using a digital projector in DLP-based 3D printing to cure photopolymer layers by CAD specifications. DLP printing provides fine control over porosity and geometry, enabling the creation of intricate structures. Furthermore, it offers superior printing resolution, speed, and cell survival compared to other 3D printing processes, including extrusion-based and laser-based procedures. This chapter highlights the advancements in biomedical applications made possible by 3D-printed MNs. It also offers an overview of the critical parameters for fabricating MNs using the 3D printing technique and their roles in drug delivery systems and hydrogel-based formulations for tissue engineering. We conclude with some observations regarding the potential applications of 3D-printed MNs.