Figure 2.

Targeted fib-GC-AuNPs are superior to non-targeted GC-AuNPs in mCT imaging of in situ carotid thrombus. A-D, Representative mCT imaging of in situ carotid thrombosis. Thrombi were formed in C57Bl/6 mice by applying stripes of filter paper (1 × 1 mm²) soaked in 10% FeCl₃ to the left distal carotid artery (photographs, upper row). Thirty minutes later, mCT thrombus images (upper row, coronal view; lower row, sagittal view) were acquired 5 minutes after intravenous injection of 200 μL GC-AuNPs (A and B) or fib-GC-AuNPs (C and D) of either a low (2 mg/kg; A-C) or high (20 mg/kg; B and D) concentration. At the low administered doses, fib-GC-AuNPs (D) outperforms GC-AuNPs (C), by more clearly marking the carotid thrombus. The “larger” thrombus in (C) vs. (A) reflects better clot visualization due to more avid binding of the targeted compound. At high administered doses, the areas of thrombus-related hyperdense lesions look similar between the animals injected with either GC-AuNPs (B) or fib-GC-AuNPs (D). E, Grouped quantification data. The above mCT imaging findings from the representative animals are corroborated by the quantification data for all 12 animals (n = 3 / group). At a higher dose (20 mg/kg), both fib-GC-AuNPs and non-targeted GC-AuNPs detected carotid thrombus with equal efficacy. At a lower dose (2 mg/kg) however, fib-GC-AuNPs and GC-AuNPs could mark approximately half and a quarter of thrombus area, respectively, as compared to the best thrombus marking result. Graphs show mean ± SEM. ^*P < 0.05 vs. GC-AuNP (both 2 mg/kg and 20 mg/kg) and fib-GC-AuNP (20 mg/kg) groups (ANOVA with post-hoc Mann-Whitney tests). Concentrations of nanoparticles are reported as 'mg Au / kg of animal'. Scale bars = 1 mm.