In vitro and in vivo assessment of CdTe and CdHgTe toxicity and clearance

Semiconductor QDs are being developed as fluorescent tags for biomedical applications such as imaging, targeting, therapeutic carriers, drug delivery, nanomedicine, and in vitro and in vivo biological labeling. However, potential toxicity and clearance of semiconductor QDs in biological systems are of concern. We have tested toxicity and clearance in vitro and in vivo (subcutaneous) of CdTe and CdHgTe semiconductor QDs in human breast cancer MCF7 and MBA-MD-231 cells and prostate cancer PC3 cells over a period of 40 days. Our results show that both CdTe and CdHgTe QDs are cytotoxic to human breast and prostate cancer cells. CdHgTe ODs were cleared rapidly from the site of injection, while CdTe were still detectable 18 days after injection, but were cleared by 30 days.