UC San Diego

Over the last decade, the use of microneedle devices has facilitated a painless localized and practical delivery of therapeutic payloads across the skin, with considerable promise in a variety of biomedical applications. However, their efficacy has been limited by the slow diffusion of molecules often requiring external actuation. This dissertation aims to demonstrate the unique advantages of active microneedle platforms. The first theme focuses on the development of an autonomous and degradable, active microneedle platform for deeper and faster intradermal therapeutic delivery, and corresponding in vivo performance in a B16F10 mouse melanoma model. The second theme explores a versatile and effective in situ active microneedle vaccination system for the direct intratumoral delivery of an immunoadjuvant, cowpea mosaic virus nanoparticles, in vivo. The third theme describes a dual-action combinatorial programmable microneedle system by integrating fast and sustained-release compartments with tunable release kinetics. We demonstrate that the fine tuning of microneedle materials allows the device to be tailored to deliver initial payloads in minutes, while simultaneously deliver a second drug over prolonged period of times ranging from weeks to months.