Comparative tissue distributions of cadmium chloride and cadmium-based quantum dot 705 in mice: Safety implications and applications

Abstract

Cadmium (Cd) is a component in quantum dot 705 (QD705). Whether QD705 behaves similar to Cd in vivo is of great concern. We compared the distributional kinetics of cadmium chloride (CdCl₂) and QD705 in mice after intravenous injection. QD705 showed a longer plasma and body retention than CdCl₂ and could be detected in the brain during early exposure. While both the liver and spleen demonstrated a constant Cd concentration for 28 days after QD705 injection, it is likely that this represents intact QD705 stored in mononuclear phagocytes. The kidneys showed a time-dependent accumulation of Cd in the QD705-exposed animals. By day 28, Cd in the kidneys from QD705 was 3-fold that of CdCl₂. QD705 and CdCl₂ have very different kinetics in distribution and metabolism. The long body retention of QD705 in the kidneys may mean that QD705 has even more renal toxicity than CdCl₂.

Keywords::

• Tissue distribution
• quantum dot 705
• cadmium
• plasma

Declaration of interest : This work was supported by grant NM-098-PP08 from the Center for Nanomedicine Research, National Health Research Institutes, Taiwan. We appreciate the assistance of Dr Jen-Kun Chen for quantifying sulfur in QD705. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.