Fig. 4
a T2-weighted magnetic resonance imaging of one xenografted tumor (circle) before and 72 h after intravenous administration of 3.5 × 1013 non-functionalized gold nanoshells (GNs) or anti-HER2 GNs, with corresponding histograms for percentage of signal initial variations (ΔSI). Each signal intensity is compared with a pre-contrast signal. b Absolute gold concentration in xenografted tumor over time after intravenous administration of non-functionalized gold nanoshells (GNs) or of 3.5 × 1013 anti-HER2 GNs using ICP-MS. Data is expressed as mean ± standard deviation, and comparisons between mice injected with non-functionalized GNs or with anti-HER2 GNs were made using Student’s t-test (*P < 0.05). c Dark field images of tumor sections at 72 h after injection of GNs. d TEM images of tumors at 72 h showing the presence of GNs within the cytoplasm of cancer cells. e Merged dark field images with immunofluorescence staining of human xenografted tumors 72 h after injection of anti-HER2 GNs, using anti-Cytokeratin (red) or anti-CD31 (green) antibodies (T: tumor; V: microvessel)