Abstract W MP34: Magnetically-Enhanced Diffusion (MED) of Intravenous tPA for Acute Ischemic Stroke: Preclinical Data

Background: Diffusion of drug to the clot in a no flow environment may be a major factor in the relative ineffectiveness of iv-tPA. The MED system uses an external magnet and magnetic particles (MP) to improve IV-tPA diffusion to clots and to mix tPA at the clot surface. Methods: Diffusion experiments were conducted in a femoral artery ligation model using Evan’s Blue dye as surrogate to tPA. Clot surface interaction experiments were conducted in a jugular vein rabbit model using thrombin-induced occlusions. tPA was locally delivered. Time to recanalization was measured out to 3hrs for 312.5U to 5000U of tPA in ~500uL of blood (0.6U/uL and 9.9U/uL, respectively), with and without MP. Results: Femoral dye studies showed a >5X faster diffusion using the MED system in the femoral artery (Figure 1). Jugular lysis studies showed greater variability in the tPA-alone arm, which possessed several failures to recanalize. No recanalization occurred in <30min for tPA doses <2500U. <25% of the 625U doses restored flo...