Figure 1.
MTT assay of L929 cell viability after various treatments.
L929 cells treated with (A) 3.5 nm CdTe QDs and (B) 2.2 nm at 2.5–240 µg/ml for 12, 24 and 48 h. Typical data from one of three independent experiments are shown with similar results compared to the control group.
Figure 2.
Representative fluorescent images showing morphological changes in L929 cells treated with CdTe QDs.
(A,I)-control treatment, (B,J) −3.5 nm CdTe 10 µg/ml treatment, (C,K) −3.5 nm CdTe 20 µg/ml treatment, (D,L) −3.5 nm CdTe 40 µg/ml treatment; (E,M)-control treatment, (F,N) −2.2 nm CdTe 10 µg/ml treatment, (G,O) −2.2 nm CdTe 20 µg/ml treatment, (H,P) −2.2 nm CdTe 40 µg/ml treatment.
Figure 3.
Annexin V-FITC/PI double staining analysis of apoptosis in L929 cells (24 h).
A: L929 cells treated with 3.5 nm CdTe QDs at 0, 10, 20 and 40 µg/ml for 24 h. B: L929 cells treated with 2.2 nm CdTe QDs at 0, 10, 20 and 40 µg/ml for 24 h. Top right quadrant, dead cells in the late stage of apoptosis; bottom right quadrant, cells undergoing apoptosis; bottom left quadrant, viable cells. C: Quantitative analysis of apoptotic cells after the treatments shown in A and B. Results represent the mean ± SD of three independent experiments. One-way analysis of variance followed by Dunnett’s post hoc test was used for statistical analysis. *p<0.05, indicates a statistically significant difference when compared to the control.
Figure 4.
Quantification of fluorescence intensity showing the relative amount of intracellular ROS formation.
ROS formation in L929 cells exposed to 0, 10, 20 and 40 µg/ml of 3.5 nm and 2.2 nm CdTe QDs for 24 h. The results were quantitatively analyzed for changes in fluorescence intensities within cells and expressed as percent units of DCF fluorescence of the control. Results represent the mean ± SD of three independent experiments. One-way analysis of variance followed by Dunnett’s post hoc test was used for statistical analysis. *p<0.05, indicates a statistically significant difference compared with the control.
Figure 5.
Confocal microscopic images which show the fluorescence intensity of intracellular calcium formation. A–D
: L929 cells treated with 3.5 nm CdTe QDs at 0, 10, 20 and 40 µg/ml (24 h). E–H: L929 cells treated with 2.2 nm CdTe QDs at 0, 10, 20 and 40 µg/ml for 24 h. I: Quantification of fluorescence intensity. Results represent the mean ± SD of three independent experiments. One-way analysis of variance followed by Dunnett’s post hoc test was used for statistical analysis. *p<0.05, indicates statistically significant difference compared with the control.
Figure 6.
Flow cytometry demonstrated changes in mitochondrial membrane potential.
L929 cells treated with 3.5 nm and 2.2 nm CdTe QDs at 0, 10, 20 and 40 µg/ml for 24 h. Mitochondria membrane potential was measured using the JC-1 Apoptosis Detection Kit. Results represent the mean ± SD of three independent experiments. One-way analysis of variance followed by Dunnett’s post hoc test was used for statistical analysis. *p<0.05, indicates statistically significant difference compared with the control.