Hyperacute direct thrombus imaging using computed tomography and gold nanoparticles.

Abstract

Advancing the understanding and management of thromboembolic stroke requires simple and robust new methods that would be useful for the in vivo assessment of thrombus burden/distribution and for characterizing its evolution in a prompt and quantitative manner. Animals (n=127) with experimental models of thrombosis were imaged with microcomputed tomography 5 minutes (and/or ~3 weeks) after intravenous injection of glycol chitosan (GC) gold nanoparticles (AuNPs). Nanoparticles accumulated in the thrombus, allowing computed tomography visualization of both the presence and extent of primary and recurrent thrombi in mouse carotid arteries without a single failure of detection. Nanoparticle thrombus imaging was also effective in monitoring the therapeutic efficacy of thrombolysis (n=118 tissue plasminogen activator [tPA] therapies). Thrombus evolution (either spontaneous or post-tPA) could be mapped at high resolution in both space and time. Due to a long circulating half-life, GC-AuNPs remain available for entrapment into fibrin matrix for an extended period of time (up to 3 weeks), allowing repetition or ongoing monitoring of thrombogenesis and thrombolysis. This is the first report on a hyperacute direct thrombus imaging technique using thrombus-seeking AuNPs and computed tomography. When translated into stroke practice, the thrombus imaging may allow us to advance to personalized thrombolytic therapy by demonstrating thrombus burden, distribution, and character in a prompt and quantitative manner. Further study into this area is indicated.