Long-Lasting Simultaneous Epidermal and Dermal Microneedle-Enabled Drug Delivery

Different skin diseases, such as cancers, inflammatory conditions, and bacterial infections, manifest at distinct skin depths. Microneedle arrays, recognized for their painless and minimally invasive drug administration, can be customized to penetrate these layers simultaneously. Here, the design of the microneedles (MNs) in nonlinear ways with diverse needle heights on the array enabling concurrent drug delivery to various skin layers is engineered. Additionally, varying the base diameter of the needles in the array facilitates prolonged or intermittent drug release, depending on the biodegradation kinetics of these needles. MNs, microfabricated with a biocompatible and biodegradable polymer, are validated by skin administration. The nonlinear design of the MNs on the array introduces a novel perspective on addressing skin diseases at varying depths of the skin.