The therapeutic efficacy of CdTe and CdSe quantum dots for photothermal cancer therapy

Fluorescent quantum dots (QDs) used for biomedical imaging and diagnostics have attracted considerable attention over the past decade. Here, we report our finding regarding the therapeutic efficacy of the popularly used red/brown, brown or close to black CdTe and CdSe QDs. Upon 671-nm laser irradiation, these QDs can rapidly convert light energy into heat, both in vitro and in vivo. In the present study, the growth of mouse melanoma tumors injected with CdTe(710) QDs coated with a silica shell (SiO2) was significantly inhibited after laser irradiation, with eventual disappearance of the tumor. In contrast, tumors injected with the silica-coated QDs without subsequent irradiation continued to grow over time. They had a growth rate close to that of tumors injected with SiO2 or phosphate-buffered saline, with or without laser irradiation. In conclusion, our data suggest that the popularly used CdTe and CdSe QDs have great potential in the treatment of cancer using photothermal therapy.