Figure 2
MWNTs mediated photothermal ablation efficiently kills cancer cells in vitro.
(A) Viabilities of MCF-7 cells and MDA-231 showed relatively low toxicity when incubated with various concentrations of MWNTs (0–100 μg/ml). The cell viability was more than 95% even when the concentration of MWNTs was up to 100 μg/ml. The bars represent means ± s.d. (n = 3). Cell viabilities of MCF-7 (B) and MDA-231 (C) were measured by CCK8 after incubation with different concentrations of MWNTs and irradiated with NIR laser at 808 nm (5 W/cm2). MWNTs plus NIR irradiation significantly decreased the cell viability while neither the MWNTs nor the NIR irradiation alone destroyed cells. Moreover, the cell viability decreased with the duration of NIR irradiation. The bars represent means ± s.d. (n = 3). Live/dead cell assays for MCF-7 (D) and MDA-231 (E) cells treated with nothing (a, e, i), laser alone (b, f, j) MWNTs alone (c, g, k) and 100 μg/ml MWNTs + Laser (d, h, l). The photothermal effect of MWNTs plus laser (d, h, l) led to a large number of dead cells (red or yellow fluorescence), but cells treated with MWNTs alone (c, g, k), laser alone (b, f, j) and nothing (a, e, i) were mostly living (green fluorescence). Fluorescence microscopy images (i-l) showed overlapping green and red fluorescence on bright field images. Magnification ×200 (a-d); magnification ×600 (e-l).
