Fig. 3.

A Cytotoxicity test of control, laser irradiation, free Dox, FeS NZs, and FeS-Dox@bLf NZs with or without laser irradiation (LR), on 4T1 cells by MTT assay. Mortality of 4T1 cancerous cells triggered by ^•OH radicals and H₂S gas after treated with FeS@bLf without (B) or with laser irradiation (LR) for 24 h (C). D Two-dimensional contour density plots of 4T1 cells obtained by flow cytometry-based assays. a: Control, b: free Dox, c: FeS-Dox@bLf NZs, and d: FeS-Dox@bLf NZs + LR. Cell necrosis and apoptosis were measured using propidium iodide (PI) and Annexin V-FITCH dyes, and (E). The effects of a: Control, free Dox, FeS-Dox@bLf NZs, and FeS-Dox@bLf NZs + LR NZs on the ROS production. Statistical differences were measured at level of ^*P < 0.05, and ^**P < 0.01