Thursday, February 23, 2012
Mechanical and Civil Engineering Seminar
Control of Magnetic Drug Targeting
Benjamin Shapiro, Assistant Professor, Fischell Department of Bioengineering and the Institute of Systems Research, University of Maryland at College Park
In magnetic drug targeting, therapy is attached or encased in magnetic carriers and external magnets are then used to direct or focus those carriers to disease locations, e.g. to tumors, infections, or blood clots. Magnetic targeting has advanced from magnetic carrier fabrication and biocompatibility studies to animal experiments and successful phase I human clinical trials (for instance for treatment of advanced inoperable head and neck tumors: Lubbe & Bergemann 1997). Our goal is to design and control magnets to better direct the magnetized drugs to where they need to go inside the body. The talk will discuss the basics of magnetic drug delivery, how magnetic forces scale with size and depth, as well as the current state of the field. I will present a spectrum of our efforts ranging from the near to the long term, and covering subjects from modeling and control design to autopsies and tissue experiments. This will include advanced but tractable numerical simulations that can accurately predict in-vivo behavior thus allowing improved design of magnetic drug delivery systems (with Oscar Bruno, Caltech). Then I will show methods for (globally) optimal magnet design to increase magnetic forces and focusing depths (with Arkadi Nemirovski). Next, I will discuss how a simple combination of magnets can create push forces thus providing drug delivery access to the inner ear through the round window membrane the inner ear is behind the blood-brain barrier and is hard to reach. This part has been validated in rat experiments. For the long term, I will present some ideas, methods, and experimental results for precision manipulation of magnetic nanoparticles methods to steer and position them under fundamental constraints (like Samuel Earnshaws classical 1837 theorem).
The talk will close with an outline of key challenges, ranging from modeling and optimization to control design, real-time nano-particle sensing, and parameter estimation from tissue, animal, and autopsy studies. Most importantly, I will try to give a sense of what kind of research fields must be combined to move magnetic drug targeting capabilities from lab to clinic.