Tumor angiogenesis targeting and imaging using gold nanoparticle probe with directly conjugated cyclic NGR

were further evaluated in a subcutaneous 4T1 xenograft model by CT imaging and immunohistochemistry study. These results showed that the GNPs-PEG@cNGR rapidly and specifically bound to the tumor vasculature after intravenous injection. Quantitative studies demonstrated that GNPs-PEG@cNGR showed significantly higher and faster tumor uptake after intravenous injection compared to unlabeled GNPs-PEG. Moreover, the distribution of tumor enhancement was consistent with the spatial distribution of angiogenic blood. These results suggest that the designed GNPs-PEG@cNGR probe may serve, in principle, as a promising CT contrast agent for targeted angiogenesis imaging and quantitative analysis.