Fig. 2 TNP-1 induced autophagy in a shape- and composition-dependent manner. a Fluorescent microscopy images of EGFP-LC3/HeLa cells treated with PBS (control) or 10 µ g mL − 1 of CuPd nanoparticles for 24 h. Scale bar, 10 µ m. The right panel shows the quanti fi ed results for the percentage of cells containing at least 5 EGFP-LC3 dots. Mean ± s.e.m. n = 5. *** p < 0.001. Student ’ s t -test. b HeLa cells were treated with PBS (control) or 10 µ g mL − 1 of CuPd nanoparticles for 24 h and then subject to western blotting with anti-LC3 and GAPDH antibodies, with the densitometric analysis shown in right. Mean ± s. e.m. n = 3. *** p < 0.001. Student ’ s t -test. c ICP-MS assay of the free copper ions (Cu 2 + ) released from 10 µ g mL − 1 CuPd TNPs and SNP in DMEM