Fig 2. Delivery efficiency of exosomes with CaCl₂ in a dose-dependent manner.

(A) Typical example of delivery of exosomes to HEK 293 cells (left panels) and H9C2 cells (right panels). (B) and (C) Delivery efficiency and cell viability of exosomes labeled with PKH26 (red) at different concentrations of CaCl₂ in HEK 293 (B) and H9C2 (C) cells. Fluorescent microscopic images (left panels), and fluorescence intensity and cell viability (right panels). The data are presented as the mean ± s.e.m. *P < 0.01.