Figure 4.

MSN internalization in hMSCs. a) Fluorescence microscopy images of hMSCs exposed to MSN_Sr, MSN_Sr‐CaP, and MSN_Sr‐CaZnP at 140 µg mL⁻¹ for 6 h. Cells stained for nuclei (DAPI; blue) and actin (phalloidin 488; green). MSNs are shown in red. Scale bars are 50 µm. b) Flow cytometry histograms of hMSCs exposed to MSN_Sr, MSN_Sr‐CaP, and MSN_Sr‐CaZnP at 140 µg mL⁻¹ for 6 and 24 h. c) Fluorescence intensity of labeled MSN_Sr‐CaZnP in supernatant after 3, 7, 14, and 21 days of culture measured by a microplate reader. Positive control (Pos. ctrl) is cell culture media with 140 µg mL⁻¹ labeled MSN_Sr‐CaZnP. d) Flow cytometry histograms of MSN_Sr‐CaZnP uptake, by hMSCs exposed to single dose and multiple doses after 3, 7, 14, and 21 days of cell culture.