Live/Dead staining
Following the protocol of the LIVE/DEAD® Viability/Cytotoxicity Assay Kit (Invitrogen, America), a working solution was prepared by combining 20 µL of EthD-1 stock solution and 5 µL of calcein AM stock solution in 10 mL of D-PBS (Meilunbio, China). This working solution was applied to cells that had undergone two washes with D-PBS. After a 30-minute incubation, fluorescence microscopy was employed to capture images.