Figure 6

The distribution of FITC-SiO₂ labeled cells in 3D culture. (a) The z-stack images of a mixture of spheroids incubated with FITC-SiO₂-COOH NPs for 24 h. (b) The z-stack images of FITC-SiO₂-COOH NPs-hFBs spheroid. The cell nuclei were visualized by Hoechst staining. The above number indicates the depth of different cell layers in the spheroid. (c) The mixed spheroid consisted of hFBs and FITC-SiO₂-COOH NPs-hUVECs. Xy, yz, and xz slices of the confocal z-stack of FITC-SiO₂-COOH (green) and Hoechst-stained cellular DNA (blue). (d) Confocal microscopy 3D reconstruction of the nucleus and distribution of FITC-SiO₂-COOH NPs.