One nanoparticle is detectable by six types of medical imaging
21 January 2015
Using two biocompatible parts, researchers have designed a nanoparticle that can be detected by six medical imaging techniques, opening the door to 'hypermodal' imaging.
Artist's impression of the particles as they are struck by beams of energy and emit signals that can be detected by the six methods (illustration courtesy of Jonathan Lovell)
The six medical imaging techniques include computed tomography (CT) scanning; positron emission tomography (PET) scanning; photoacoustic imaging; fluorescence imaging; upconversion imaging; and Cerenkov luminescence imaging. In the future, patients could receive a single injection of the nanoparticles to have all six types of imaging done.
This kind of 'hypermodal' imaging — if it came to fruition — would give doctors a much clearer picture of patients’ organs and tissues than a single method alone could provide. It could help medical professionals diagnose disease and identify the boundaries of tumours. The work was conducted by researchers at the University at Buffalo (UB).
“This nanoparticle may open the door for new ‘hypermodal’ imaging systems that allow a lot of new information to be obtained using just one contrast agent,” says UB researcher Jonathan Lovell. “Once such systems are developed, a patient could theoretically go in for one scan with one machine instead of multiple scans with multiple machines.”
A machine capable of performing all six imaging techniques at once has not yet been invented, to Lovell’s knowledge, but he and his co-authors hope that discoveries like theirs will spur development of such technology.
The researchers designed the nanoparticles from two components: an 'upconversion' core that glows blue when struck by near-infrared light, and an outer fabric of porphyrin-phospholipids (PoP) that wraps around the core. Each part has unique characteristics that make it ideal for certain types of imaging.
The core, initially designed for upconversion imaging, is made from sodium, ytterbium, fluorine, yttrium and thulium. The ytterbium is dense in electrons — a property that facilitates detection by CT scans.
The PoP wrapper has biophotonic qualities that make it a good match for fluorescence and photoacoustic imagining. The PoP layer is also adept at attracting copper, which is used in PET and Cerenkov luminescence imaging.
Lovell says the next step in the research is to explore additional uses for the technology.
For example, it might be possible to attach a targeting molecule to the PoP surface that would enable cancer cells to take up the particles, something that photoacoustic and fluorescence imaging can detect due to the properties of the smart PoP coating. This would enable doctors to better see where tumours begin and end.