(Images: Edward A. Sykes & Qin Dai)

They may look like something captured by the Hubble telescope, but these mice are revealing more about their inner space than what’s in outer space. The fluorescent speckles, spots and clouds marking their bodies are nanoparticles lodged within their skin and rendered visible with ultraviolet light.

Nanoparticles are increasingly being used in water treatment, food packaging, cosmetics and as pesticides, prompting concerns about the health effects of long-term exposure. Yet until now, it has been difficult to quantify the accumulation of nanoparticles within tissues, without destroying them.

These images show mice injected with nanoparticles called quantum dots – light-sensitive, semiconducting particles just a few nanometres in diameter. The particles can be seen though the skin when the mice are exposed to UV light using a technique called inductively coupled plasma atomic emission spectroscopy.


Warren Chan of the University of Toronto in Canada found that the concentration of these particles in the skin directly correlates with both the injected dose and their accumulation in other organs. His team hopes that this discovery could be used to better predict how nanoparticles behave in the body.

Journal reference: Nature, DOI: 10.1038/ncomms4796