Colloquium: Dr. Didier Depireux, UMD

TITLE: Magnetically-driven nanoparticle drug delivery: where physics meets biology

ABSTRACT: Novel, active delivery systems based on emerging nanotechnologies show great promise for direct and safe delivery of medications. The current approach to pharmacotherapy typically involves systemic administration of medications at doses high enough to be efficacious at target sites where drug access is limited. This leads to adverse side effects due to drug action in tissues where no drug is needed. We have shown that nanoparticles may serve as a means for precise, extended delivery of anti-inflammatory, antimicrobial, or regenerative compounds into target tissues that are notoriously difficult to reach. We have developed a method to magnetically push drug-loaded, magnetic core nanoparticles to the ear to treat hearing loss and tinnitus, to infections and inflammation in teeth, and to target deep brain structures. We have shown that the nanoparticles are non-toxic, and allow us to reach drug concentrations at therapeutic levels at discrete locations, all while avoiding systemic exposure.

However, many challenges remain in transporting nanoparticles across diverse biological barriers and matrices, each presenting its own challenges. For instance, smaller particles are better able to cross biological barriers, but experience less magnetic force. On the other hand, stronger magnetic gradients result in stronger applied forces but result in particles clustering, increasing their effective size. Unresolved issues and challenges in magnetic nanoparticles-assisted drug delivery will be presented