Deeper than ever bio images thanks to new nanotech

The technology, developed by teams from several universities in the US, China and Sweden, is made up of photoluminescent nanoparticles encased in a calcium-floride shell.

Once in-situ, the particles take on a process called near-infrared-to-near-infrared up-conversion – or NIR-to-NIR – which emits light differently to the biological molecules surrounding it.  

The uptick is that the particles can create a glow visible through more than three centimetres of biological tissue – deeper than previously thought possible.

The researchers say the findings could help bridge the gap between in vitro​ and in vivo ​studies, and could mean a host of new information about drug delivery and how therapies work in the body.

“Though optical imaging is a robust and inexpensive technique commonly used in biomedical applications, current technologies lack the ability to look deep into tissue,”​ a statement on behalf of the team said, adding that there is a high demand for deep-tissue imaging tech.

Gang Han, an assistant professor at University of Massachusetts Medical School who co-led the study, added: "We expect that the unprecendented properties in the core/shell nanocrystals we designed will bridge numerous disconnections between in vitro and in vivo studies, and eventully lead to new discoveries in the fields of biology and medicine."​

How it works​

The nanoparticles are made up of a nanocrystalline core containing thulium, sodium, ytterbium and fluorine. The core is then placed inside a square, calcium-fluoride shell.

The tech allows deeper than previously thought imaging because the particles absorb infrared light and then emit it with a much shorter wavelength – therefore acting differently to its natural environment.

As the shell material is made up of calcium fluoride, it is also highly bioavailable. “This makes the particles compatible with human biology, reducing the risk of adverse effects,”​ a spokesperson for the paper, published in ACS Nano added.

The nanocrystals have so far only been tested in mice and a slice of pork more than 3 centimeters thick.

According to lead researcher Guanying Chen, research assistant professor at the Institute for Lasers, Photonics and Biophotonics, Buffalo, the next round of research will focus on targeting cancer cells and other biologic targets.

Chen added that the researchers are hopeful the technology will become a platform for multimodal bioimaging.