Fig. 8

a In vivo biodistribution of A549 tumour-bearing nude mice intravenously injected with DiR/C-NPs or free DiR solution 1, 4, 12 and 24 h after injection. The tumour foci are marked with red circles. b Ex vivo biodistribution 24 h after intravenous injection of DiR/C-NPs or free DiR for tumour (T) and major organs of heart, liver, spleen lung and kidney (abbreviated respectively as H, L, S, Lu and K). c General resident efficiency of organs removed 24 h following the injection of DiR/C-NPs or DiR. **p < 0.01. d Fluorescence distribution of C6/C-NPs in A549 solid tumour with/without ultrasound treatment. Scale bar denotes 20 µm. e Fluorescent intensity of C6/C-NPs with/without ultrasound treatment was recorded along a straight line from the tumour surface to the interior