Fig. 4.

In vitro cytotoxicity profiles and intracellular catalytic mechanism. In vitro 4T1 (a) and U87 (b) cytotoxicity profiles of GFD NCs under neutral (pH = 7.4) and acidic (pH = 6.0) conditions. l-ascorbic acid-assisted cell rescue profiles of (c) 4T1 and (d) U87 cancer cells’ cytotoxicity induced by 12.5 μg ml⁻¹ of GFD NCs. Mean values and error bars are defined as mean and s.d., respectively. Experiments were performed in quadruplicate. e CLSM images of viable and dead cell distributions after co-incubation with GFD NCs at varied concentrations: 2.5, 5, and 10 μg ml⁻¹ under neutral (pH = 7.4) and acidic (pH = 6.0) conditions for 4 h and subsequently stained with calcein-AM/PI solutions. f CLSM images of 4T1 cells after co-incubation with DMSN, FD NCs, and GFD NCs under neutral (pH = 7.4) and acidic (pH = 6.0) conditions for 4 h and subsequently stained with ROS fluorescence probe DCFH-DA