ICAM-1-Carrying Targeted Nano Contrast Agent for Evaluating Inflammatory Injury in Rabbits with Atherosclerosis 

Purpose: To investigate the feasibility of using ICAM-1-carrying targeted nano ultrasonic contrast to evaluate the degree of inflammatory injury at different stages in the abdominal aorta of rabbits with atherosclerosis (AS). Methods Twenty-five experimental rabbits were assigned to five groups: the preoperative control group (A); the week-4 after modeling group(B); the week-8 after modeling group(C); the week-12 after modeling group(D); the week-16 after modeling group(E). All groups were given 2D ultrasonography, conventional ultrasonic contrast (SonoVue), and ICAM-1-carrying targeted nano ultrasonic contrast, respectively. Contrast parameters, including the peak intensity (PI), time to peak (TTP), and area under curve (AUC) of the region of interest, were used to evaluate the characteristics of vascular perfusion contrast. Results ICAM-1-carrying targeted nano ultrasonic contrast showed that the intensity of targeted micro-signals in the vascular wall of the abdominal bubble aorta gradually increased in B, C, D, and E groups (all P < 0.05). A positive linear correlation between PI and AUC and the expression of ICAM-1 (r = 0.893, P  < 0.001; r = 0.934, P  < 0.001). In ICAM-1-carrying targeted nano ultrasonic contrast, delayed imaging of the vascular wall of the abdominal aorta was observed, the outer membrane was thickened from week 4 to week 12, and both the intima-media membrane and outer membrane were thickened and with double-layer parallel echo at week 16, which was in line with the progression of atherosclerotic plaque vulnerability. Conclusion ICAM-1-carrying targeted nano contrast agent could evaluate the degree of inflammatory injury related to atherosclerotic progression and site high expression of specific adhesion molecules in early atherosclerotic lesions.