GOALI: Convective Delivery of Clot-Busting Drugs to Dead-End Arteries for Stroke Victims by Magnetically Driven Flows

University Of Texas At Austin, Austin TX

Investigators

Abstract

CBET 1437354 Bonnecaze, Roger T. GOALI: Convective Delivery of Clot-Busting Drugs to Dead-End Arteries for Stroke Victims by Magnetically Driven Flows When flow through a liquid-filled tube is blocked because of an obstruction, it is difficult to deliver chemical agents that could remove the obstruction and restore flow through the channel. Partial or complete obstruction of flow can occur in a variety of situations, perhaps most notably in stroke victims whose cerebral blood flow is blocked owing to a blood clot in a vessel. Delivering drugs such as tissue plasminogen activator (tPA) that can dissolve a clot and restore blood flow is a challenge because the drug must diffuse to the clot, which is slow and often ineffective. This GOALI project will explore the use of micron-sized iron particles in a magnetic field that can cause fluid mixing in blocked channels and improve transport of tPA along the length of the vessel to the clot. Investigators at The University of Texas and Pulse Therapeutics, Inc. will conduct a series of experiments and numerical simulations to analyze the flow induced by the particles and optimize transport of clot-dissolving agents in blocked vessels. The results of the project could improve the effectiveness of tPA therapy, and be helpful in a diverse array of technological applications, including using surfactants to remove trapped water in shale and tight gas-sand reservoirs to improve oil and gas production. This GOALI project will develop an experimentally validated model and simulation of magnetically driven convection of iron-containing fluid to understand how the strength of the magnetic field, its gradient and rotation rate generate flow and the sensitivities of the flow to these parameters. The simulation tool will help optimize design of the magnetic system and selection of particle properties. At the particle scale conservation equations will describe the local concentration of free particles and particles that chain together to form rods, including the formation and destruction of the rods due to the applied magnetic field, shear flow and interactions with the walls of the vessels. It is hypothesized that these rods rotate in the field and generate localized vorticity that drives the macroscopic convective flow in the vessel. At the vessel scale conservation of mass and momentum equations will describe this magnetically-induced vorticity driven flow. The model equations will be solved asymptotically and numerically to understand this unique process for creating convective flows in dead-end or blocked vessels. Complementary experiments conducted by research team at Pulse Therapeutics will validate the model and indicate modifications as necessary.