Figure 7: NIRF molecular imaging of oxLDL in atherosclerotic balloon injured rabbit abdominal aortae.

LO1-750 (6.6 mg/kg in this example) was injected IV into rabbits with aortic atherosclerosis following balloon injury and HF feeding. (A) Shows conventional angiography of the rabbit aorta with the red box indicating the balloon injured area; (B) demonstrates the corresponding longitudinal IVUS catheter pullback through the aorta. The white arrows in (B) demarcate IVUS evidence of eccentric atherosclerotic plaque; (C) shows ex vivo two-dimensional (2D) intravascular NIRF imaging of in vivo LO1-750 localization after 21 hours. There are two distinct ‘hot spots’ seen on the intravascular 2D NIRF (white arrows in (C,D). The SNR of the 10 mm long plaque at the 34 mm to 35 mm mark was 86.4 and target to background ratio (TBR) was 4.8 (yellow/white: higher NIRF signal intensity, red/: lower NIRF signal intensity –arbitrary NIRF units); (D) demonstrates corresponding ex vivo FRI (740/790 nm) with augmented NIRF LO1-750 activity in the two ‘hot spots’ seen on intravascular imaging. Corresponding lesions are linked by the dotted blue line; (E) demonstrates fluorescence microscopy of a cryosection from the larger lesion of the aorta shown in (C–D). The left panel in (E) is LO1-750 fluorescence (red) in the NIR channel showing focal and diffuse localization to constituents of plaque, the middle panel shows the distinctly different atherosclerosis autofluorescence pattern in the FITC channel (green), whilst the right panel is a merged image of both; Scale bars in represent 10 mm in (A–D) and 50 μm in (E).