Flow dynamics of biolistic drug-delivery and therapeutic microparticles*

The needle- and syringe-based delivery of vaccines and other therapeutics have been of great benefit to human health but there are some critical issues, including the shortage of medical personnel, increasing biohazard waste, and cross-contamination risks. As such, alternate skin-based delivery routes are of significant interest, with biolistic delivery emerging as a promising option. In this study, we focus on the flow dynamic aspects of a novel biolistic delivery method, called "MOF-Jet"[TH1] , which uses a carrier gas to deliver a payload of drug-loaded metal-organic frameworks, as an alternative to needle-based administration methods. The process is modeled with a coupled Lagrangian-Eulerian framework, in which the drug particles are injected into a porous medium using a high-speed flow. This four-way coupling method models flow-particle interactions, including particle collisions. The MOF-Jet is a jet-crafted tube that accelerates drug particles at the nozzle throat and directs them into the porous medium. The numerical results showed excellent agreement with measurements and revealed intricate flow structures that can enhance drug delivery efficiency. The interactions between particles and porous skin are also explored through instantaneous flow dynamics. This study lays the milestone for future research on optimizing the biolistic design, offering a promising alternative to conventional techniques.