Title: High-Resolution 3D Printing of Microarray Patches for Transdermal Applications

Abstract: Intradermal (ID) drug delivery offers a minimally invasive method to administer formulations into the skin, enabling localized treatment with reduced pain, a lower risk of blood-borne disease transmission, and less medical waste. Microneedle Array Patches (MAPs) are a promising approach for ID access, consisting of micrometer-sized projections that painlessly penetrate the skin’s epidermal and dermal layers. MAPs are being developed as self-administrable, needle-free alternatives to traditional hypodermic injections and have applications in drug delivery and diagnostic sampling of interstitial fluid (ISF).

Despite their potential, current MAP designs are constrained by manufacturing limitations, which typically involve complex, multi-step processes borrowed from the microelectronics industry, such as silicon etching and molding. We propose a new framework to classify MAPs by their fabrication methods (Generations 1.0–4.0), highlighting advances in 3D printing and direct fabrication (Generations 3.0 and 4.0) that enable more flexible and innovative MAP designs. Particularly, we present new MAP geometries created using high-resolution Continuous Liquid Interface Production (hi-res CLIP), a 3D printing technique developed in the DeSimone Lab. These include latticed micro-array patches (L-MAPs), dynamic MAPs (D-MAPs), and fluidically-backed MAPs, offering enhanced functionality for drug delivery, complex geometries with improved cargo loading capacity and  more consistent delivery profiles. L-MAPs, in particular, enable modular drug delivery, allowing for customizable needle geometries and cargo formulations (e.g., small molecules, proteins, and nucleic acids) that can be combined into hybrid patches with multiple release profiles. We explore the use of L-MAPs for clinical applications, including RNA-based SARS-CoV-2 vaccines and live attenuated measles vaccines. Finally, we introduce a 3D-printed MAP device for rapid ISF sampling in human volunteers, enabling proteomic and transcriptomic analysis. This idea is then connected back to the L-MAP platform, demonstrating its potential for integrated drug delivery and diagnostic functions. In this work, we aim to showcase how additive manufacturing can revolutionize MAP technology, creating new possibilities for minimally invasive drug delivery and diagnostic platforms.

Please contact Madelyn Bernstein for the Zoom link