Quantum Dots Linger In Mouse Tissue | June 22, 2009 Issue - Vol. 87 Issue 25 | Chemical & Engineering News
Volume 87 Issue 25 | p. 35 | Concentrates
Issue Date: June 22, 2009

Quantum Dots Linger In Mouse Tissue

Fluorescence imaging reveals that the flashing nanoparticles can persist for years in mice, although the long-term toxicity is still uncertain
Department: Science & Technology
Keywords: quantum dots, metal toxicity
This two-photon fluorescence image of a mouse lymph node shows quantum dots that have lingered there for two years.
Credit: James Fitzpatrick
8725scon_lymphnode
 
This two-photon fluorescence image of a mouse lymph node shows quantum dots that have lingered there for two years.
Credit: James Fitzpatrick

Quantum dots could become fantastic contrast agents for medical imaging, but the glittering nanoparticles typically are made from toxic metals, and researchers don't know how long they remain in the body or whether they gradually dissolve. To shed light on those questions, Marcel P. Bruchez and colleagues of Carnegie Mellon University injected ZnS-coated CdSe quantum dots into mice and examined them with fluorescence imaging techniques (Nano Lett., DOI: 10.1021/nl901534q). Within days, the dots were undetectable in liver tissue, but they remained in bone marrow for months. Two years later, new images disclosed that some quantum dots still lingered in the animals' lymph nodes. The nanoparticles' emission spectra changed considerably, however, raising the possibility that they partially dissolved. The researchers conclude that quantum dots don't spill their metal contents quickly enough to pose an acute health risk, but it is unclear if the nanoparticles might cause chronic metal toxicity. They argue that quantum dots should be engineered to exit the body rapidly and should not be made from toxic metals, even if they have a sturdy shell.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

Leave A Comment

*Required to comment