Biphasic Co-Delivery of Curcumin and 5-FU using 3D-Printed Dissolving Microneedles for Skin Cancer Therapy

Dissolving microneedle (MN) arrays are a minimally invasive strategy for localized transdermal chemotherapy; however, their translation is limited by drug loading, reproducible dosing, and the difficulty of incorporating chemically distinct drugs into printable matrices. Although MN-mediated delivery of curcumin and 5-fluorouracil (5-FU) has previously been reported using inkjet/coating-based approaches, those systems deposit drug formulations onto preformed solid MNs and are therefore constrained by surface coating uniformity, limited matrix integration, possible drug loss during handling, and less direct control over geometry-dependent dose. Here, we report a distinct one-step DLP 3D-printing strategy in which hydrophilic 5-FU and hydrophobic curcumin are incorporated directly into a single PEGDA/VP photocurable resin before fabrication. The optimized resin enabled high-resolution MN arrays with CAD-defined dimensions, sharp tips, insertion efficiency above 95%, high drug entrapment, and controlled/biphasic release behavior. Importantly, the work demonstrates that curcumin's optical absorbance can be managed through exposure optimization without compromising print fidelity, allowing dual-drug-loaded dissolving MNs to be manufactured directly from the therapeutic resin. These findings establish the system as a formulation-process-performance platform rather than a first report of curcumin/5-FU MN co-delivery, providing a scalable and customizable approach for localized skin-cancer drug delivery that warrants future biological validation.