Good Breaks: Circumventing Biological Barriers to Drug Delivery

Dr. Tyrone Porter
Associate Professor
Department of Mechanical Engineering and Biomedical Engineering
Boston University
Monday, March 21
4:00 – 5:00 pm
SEH Lehman Auditorium, B1220


Cells and tissues are equipped with biological barriers, such as cell membranes and the blood-brain barrier, that provide protection against invading pathogens. Unfortunately, these barriers inhibit the delivery of therapeutic agents and thus are a major impediment to the pharmaceutical intervention of disease. Penetrating these barriers and thus enabling the use of potent and innovative therapeutic agents has become a key focus of ongoing research in my group. In one project, we use a combination of ultrasound and vaporizable nanodroplets to permeabilize cell membranes for siRNA delivery. We achieve efficient delivery while maintaining high cell viability, thus addressing a limitation that has plagued siRNA delivery for years. In a second project, ultrasound is used to drive encapsulated microbubbles and reversibly open the blood-brain barrier. Using liposomes labeled with fluorophores and MR contrast agents, we have investigated the relationship between particle size and penetration across the disrupted BBB. Lastly, we have developed a dynamic model of the BBB, which can be used to identify and screen ligands that facilitate receptor-mediated transcytosis (RMT) across the BBB. We have explored RMT of nanoparticles across the BBB under flow conditions, which is more relevant to in vivo conditions than conventional in vitro experiments based upon static transwell culture dishes. Overall, we are developing tools and techniques for bypassing biological barriers to drug delivery and usher and enabling the treatment of previously inaccessible diseases.



Tyrone Porter is an Associate Professor in the Departments of Mechanical Engineering and Biomedical Engineering and the Division of Materials Science and Engineering at Boston University. In 2006, he founded the Nanomedicine and Medical Acoustics Laboratory (NanoMedAL) with the goal of integrating materials science, biology, and physics to engineer constructs and platforms for predictable, efficient, and controlled delivery of diagnostic and therapeutic agents. Additionally, he is an Associate Director for the Nanotechnology Innovation Center (BUnano), an Associate Director for the NIH-funded Translational Research in Biomaterials (TRB) training program, and a member of the Cancer Research Center at Boston Medical Center. Dr. Porter earned a bachelor’s degree in Electrical Engineering from Prairie View A&M University in Texas and completed his graduate work in the Department of Bioengineering at the University of Washington. He was awarded the Frederick V. Hunt Postdoctoral Fellowship and the R. Bruce Lindsay award from the Acoustical Society of America in 2003 and 2008, respectively.