Fig. 2.

Cytotoxicity and cellular uptake of the NPs. Cell viability of MSCs after cocultured with (a) CuS and (b) CuS@PC NPs with various concentration for 24 h. (c) Fluorescence intensity of MSCs engineered with the Cy5.5-labeled NPs. Fluorescence intensity was measured from five images acquired from random positions of the samples. (d) Representative fluorescent images of MSCs engineered with the Cy5.5-labeled NPs. Cellular uptake of the NPs was higher (stronger red fluorescence) in CP-MSCs relative to C-MSCs. Data are presented as means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.