3D‐Printed Latticed Microneedle Array Patches for Tunable and Versatile Intradermal Delivery

Abstract Using high‐resolution 3D printing, a novel class of microneedle array patches (MAPs) is introduced, called latticed MAPs (L‐MAPs). Unlike most MAPs which are composed of either solid structures or hollow needles, L‐MAPs incorporate tapered struts that form hollow cells capable of trapping liquid droplets. The lattice structures can also be coated with traditional viscous coating formulations, enabling both liquid‐ and solid‐state cargo delivery, on a single patch. Here, a library of 43 L‐MAP designs is generated and in‐silico modeling is used to down‐select optimal geometries for further characterization. Compared to traditionally molded and solid‐coated MAPs, L‐MAPs can load more cargo with fewer needles per patch, enhancing cargo loading and drug delivery capabilities. Further, L‐MAP cargo release kinetics into the skin can be tuned based on formulation and needle geometry. In this work, the utility of L‐MAPs as a platform is demonstrated for the delivery of small molecules, mRNA lipid nanoparticles, and solid‐state ovalbumin protein. In addition, the production of programmable L‐MAPs is demonstrated with tunable cargo release profiles, enabled by combining needle geometries on a single patch.