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Nanoparticles Light Up Deep-Tissue Cancers

Researchers have engineered nanoparticles that light up to reveal disease biomarkers found in deep tissue. The technology opens up a new avenue in minimally invasive disease diagnosis.

“Specially designed nanoparticles can be placed in biological samples or injected into specific sites of the body and then ‘excited’ by introduced light such as that from a laser or an optical fibre,” says research author Dr Yiqing Lu of the ARC Centre of Excellence for Nanoscale BioPhotonics. “Disease biomarkers targeted by these nanoparticles then reveal themselves by emitting their own specific wavelength signatures, which are able to be identified and imaged.”

However, so far only a single disease biomarker at a time could be distinguished and quantified in the body using this type of detection technique. “The tissue environment is extremely complex – full of light-absorbing and -scattering elements such as blood, muscle and cartilage,” Lu explains. “And introducing multiple nanoparticles to a site, operating at multiple wavelengths to detect multiple biomarkers, produces too much interference. It makes it extremely difficult to determine accurately if a range of disease biomarkers are present.”

Lu’s research team has addressed this issue by engineering nanoparticles that emit light at the same frequency but can be coded to emit light for set periods of time, from microseconds to milliseconds. “It is the duration of the light emission, and the biomarker reaction to this timed amount of light, that produces a clearly identifiable molecular signature,” he says.

“Multiple disease biomarkers can be clearly identified and imaged based on this approach as there are no overlapping wavelengths interfering with the reading. This enables high-contrast optical biomedical imaging that can detect multiple disease biomarkers all at the one time.”

Already the technique, which has been published in Nature Nanotechnology (https://goo.gl/Bqs5Ff), has detected different forms of breast cancer tumours in mice.