Figure 4.

In vitro photothermal effects in A375 cells. (A) Confocal microscope image of cells treated with NaYF₄:Yb,Er@PE₃@Fe₃O₄ nanoprobes and stained with Prussian blue, indicating our nanoprobes were readily taken up by A375 cells. (B) Bright-field images of A375 cells treated with saline or nanoprobes, in the presence or absence of near-infrared (NIR) irradiation. The combination of nanoprobes with NIR irradiation led to overt cell death. This experiment was repeated three times. (C) MTT assay showing the viability of A375 cells treated with increasing concentrations of nanoprobes in the presence and absence of NIR irradiation (n=3). (D) Apoptotic and necrotic rates of A375 cells after photothermal treatment as revealed by flow cytometry. This experiment was repeated three times. (E) Expression of heat shock protein HSP70 was elevated with increasing concentrations of nanoprobes in the presence of NIR irradiation, on both mRNA and protein levels as revealed by semiquantitative PCR and western blot, respectively. This experiment was repeated three times.