Investigation of Nanodroplet Adhesion to Endothelial Cells under Atheroprone Flow Conditions

Ultrasound molecular imaging, using microbubbles targeted to the activated endothelium that is involved in the initiation and progression of atherosclerosis, could improve risk stratification for atherosclerotic complications. Nanodroplets, may have advantages over microbubbles as they have smaller dimensions, a longer in vivo circulation time, and activation that can be controlled in both space and time. The aim of this study is to investigate the passive adherence of perfluorocarbon nanodroplets to endothelial cells exposed to atheroprotective versus pro-atherogenic flow conditions in vitro. The results show the acoustic amplitude on the endothelial cells at the centre of the well is on average 5 times higher than the ultrasound signal on the cells at the edge of the well. The microscopic images show that nanodroplets adhered to cells sheared with pro-atherogenic flow, but not to the cells sheared with atheroprotective flow, even without a receptor targeting mechanism. This finding could be developed further to develop a novel technique to non-invasively detect the early development and progression of atherosclerosis, without the need for receptor conjugation to the agents.