Long circulation and tumor targeting of DOX@CAuNCs. (A) Intracellular Au contents in RAW264.7 cells treated with AuNCs, CAuNCs or DOX@CAuNCs at Au concentration of 10 μg/mL in the absence of FBS for different time intervals. (B) In vivo pharmacokinetics in SD rats after intravenous injection with AuNCs, CAuNCs or DOX@CAuNCs at Au dose of 10 mg/kg. (C) Intracellular Au contents in H22 cells treated with AuNCs, CAuNCs or DOX@CAuNCs at Au concentration of 10 μg/mL in the absence of FBS for different time intervals. (D) Cell viability of H22 cells treated with CCM, DOX, AuNCs, CAuNCs or DOX@CAuNCs at Au and DOX concentration of 10 and 1.5 μg/mL for 12 h, correspondingly, followed by 808 nm laser irradiation (1 W/cm2) for 5 min and then incubation in fresh medium for 8 h. (E) In vivo biodistribution of AuNCs, CAuNCs or DOX@CAuNCs in H22 tumor-bearing mice at 48 h after intravenous injection at Au dose of 10 mg/kg. Data as mean value ± SD (n=4). *P<0.05, **P<0.01, ***P<0.001.