• S Subramanian, S O Ugoya, Z Zhao, L S McRobb, G E Grau, V Combes, D W Inglis, A J Gauden, V S Lee, V Moutrie, E D Santos, and M A Stoodley.
• Department of Clinical Medicine, Macquarie University, Sydney 2109, Australia.
• Thromb. Res. 2018 Jul 1; 167: 104-112.

BackgroundOur goal is to develop a vascular targeting treatment for brain arteriovenous malformations (AVMs). Externalized phosphatidylserine has been established as a potential biomarker on the endothelium of irradiated AVM blood vessels. We hypothesize that phosphatidylserine could be selectively targeted after AVM radiosurgery with a ligand-directed vascular targeting agent to achieve localized thrombosis and rapid occlusion of pathological AVM vessels.ObjectiveThe study aim was to establish an in vitro parallel-plate flow chamber to test the efficacy of a pro-thrombotic conjugate targeting phosphatidylserine.MethodsConjugate was prepared by Lys-Lys cross-linking of thrombin with the phosphatidylserine-targeting ligand, annexin V. Cerebral microvascular endothelial cells were irradiated (5, 15, and 25 Gy) and after 1 or 3 days assembled in a parallel-plate flow chamber containing whole human blood and conjugate (1.25 or 2.5 μg/mL). Confocal microscopy was used to assess thrombus formation after flow via binding and aggregation of fluorescently-labelled platelets and fibrinogen.Results And ConclusionsThe annexin V-thrombin conjugate induced rapid thrombosis (fibrin deposition) on irradiated endothelial cells under shear stress in the parallel-plate flow device. Unconjugated, non-targeting thrombin did not induce fibrin deposition. A synergistic interaction between radiation and conjugate dose was observed. Thrombosis was greatest at the highest combined doses of radiation (25 Gy) and conjugate (2.5 μg/mL). The parallel-plate flow system provides a rapid method to pre-test pro-thrombotic vascular targeting agents. These findings validate the translation of the annexin V-thrombin conjugate to pre-clinical studies.Copyright © 2018 Elsevier Ltd. All rights reserved.

15 keywords...

hide…