2.10. Cell apoptosis assay

Cell apoptosis was detected using Annexin V‐APC and Propodium Iodide (PI) staining (Biolegend, USA) according to the manufacturer's instructions. After treating MOLM13 cells with 15 μg ASO‐loaded RBCEVs for 72 h, the cells were washed twice with cold PBS and then resuspended in 100 μl Annexin V binding buffer. 5 μl of APC Annexin V and 10 μl of PI were added into cells followed by gentle vortexing of the cells and incubation for 15 min at room temperature in the dark. Before flow cytometry analysis, 400 μl of Annexin V binding buffer was added to each tube, and the samples were analysed using flow cytometry within 1 h.