Figure 2.

Cellular uptake and bioimaging of SF-NPs in in vitro, and in vivo tests of long-term culture of hMSCs after transfection. (A) Cellular uptake of SF-NPs, as determined by TEM. (a) Control (non-transfected cells: NT1 cells); (b) SF-NP-transfected hMSCs (T1 cells), near the cell membrane; (b-1) SF-NP-transfected hMSCs (T1 cells), near early endosomes; (c) control (non-transfected cells: NT4 cells); (d) SF-NP-transfected hMSCs (T4 cells), near the cell membrane; (d-1) SF-NP-transfected hMSCs (T4 cells), near early endosomes. Red arrows indicate QDs. Bar, 500 nm. (B) Cellular uptake of SF-NPs, as determined by confocal laser microscopy. (a) SF-NP-transfected hMSCs (T1 cells), near the cell membrane; (b) SF-NP-transfected hMSCs (T1 cells), near early endosomes; (c) Control (T1 cells); (d) SF-NP-transfected hMSCs (T1 cells), near early endosomes. Red particles indicate QDs. Bar, 20 μm. (C) Green fluorescent protein (GFP)-tagged SOX9 expressed on hMSCs, and remaining QDs in hMSCs after SF-NP transfection. (a) Control cells (NT1 cells); (b) GFP-expressing hMSCs (green) and remaining QDs (red) (T1 cells); (c) control (NT4 cells); (d) GFP-expressing hMSCs (green) and remaining QDs (red) (T4 cells). Bar, 20 μm. (D) QDs remaining in hMSCs after transfection, as determined by FACS analysis. (a) Control cells (NT1 cells); (b) GFP-expressing hMSCs and remaining QDs (T1 cells); (c) control (NT4 cells); (d) GFP-expressing hMSCs and remaining QDs (T4 cells). (E) Fluorescence intensities of EGFP and QDs expressed in hMSCs, and bioimaging of hMSCs after transplantation. (a) Fluorescence intensities of EGFP and QDs in hMSCs (T1, T2, T3, and T4 cells). (b) SF-NP-transfected hMSCs (T1 cells). Bar, 20 μm. (c) SF-NP-transfected hMSCs (T4 cells). Bar, 20 μm. (d) Bioimaging of QDs transfected into hMSCs (T1 cells), which were then transplanted into a nude mouse. (e) Bioimaging of QDs transfected into hMSCs (T4 cells), which were then transplanted into a nude mouse.