Published January 26, 2015 This content is archived.
An international team led by Jonathan F. Lovell, PhD, assistant professor of biomedical engineering, has created a nanoparticle that may pave the way for “hypermodal” imaging — the ability to merge results from six different imaging modes using one contrast agent.
“If such systems are developed, a patient could theoretically go in for one scan with one machine and receive a single injection of the nanoparticles, eliminating the need for multiple scans with multiple machines,” says Lovell.
Although no machine currently exists that can perform all six imaging techniques at once, the researchers hope their findings will spur the development of such technology.
“The potential future technology would give medical professionals a much clearer picture of patients’ organs and tissues, helping to improve diagnoses and identify the boundaries of tumors,” Lovell predicts.
The researchers’ novel nanoparticle can be detected by computed tomography (CT) and positron emission tomography (PET) scanning, as well as photoacoustic, fluorescence, upconversion and Cerenkov luminescence imaging.
It consists of two biocompatible parts, each with unique characteristics that respond to certain types of imaging.
An outer fabric of porphyrin-phospholipids (PoP) wraps around a core that glows blue when struck by near-infrared light.
The PoP wrapper has biophotonic qualities that respond well to fluorescence and photoacoustic imaging. It also is adept at attracting copper, used in PET and Cerenkov luminescence imaging. The core — originally designed for upconversion imaging — contains electron-dense ytterbium that also facilitates detection by CT scans.
When the research team used their nanoparticles to examine the lymph nodes of mice, they found that CT and PET scans provided the deepest tissue penetration, while photoacoustic imaging showed blood vessel details that other modalities missed.
“Combining these two biocompatible components into a single nanoparticle could give tomorrow’s doctors a powerful new tool for medical imaging,” says Paras N. Prasad, PhD, another lead researcher on the project who directs the University at Buffalo’s multidisciplinary Institute for Lasers, Photonics and Biophotonics (ILPB).
The researchers envision numerous possible applications for the technology.
“The core-shell imaging contrast agent could enable biomedical imaging at multiple scales — from single-molecule to cell imaging, and from vascular and organ to whole-body bioimaging,” says Guanying Chen, PhD, another lead researcher on the project affiliated with the ILPB and Harbin Institute of Technology in China.
“These broad, potential capabilities are due to a plurality of optical, photoacoustic and radionuclide imaging abilities that the agent possesses.”
In addition, the technology may aid cancer assessment and treatment.
If a targeting molecule could be attached to the PoP surface, cancer cells could take up the particles and be detected via photoacoustic and fluorescence imaging.
“This would enable doctors to better see where tumors begin and end,” Lovell says.
“More studies would have to be done to determine whether the nanoparticle is safe to use for these purposes,” notes Prasad, also a SUNY Distinguished Professor of chemistry, physics, medicine and electrical engineering.
“However, the nanoparticle we created does not contain toxic metals, such as cadmium, that pose potential risks and are found in some other nanoparticles.”
The research, “Hexamodal Imaging with Porphyrin-Phospholipid-Coated Upconversion Nanoparticles,” has been published in Advanced Materials.
Contributors include three UB biomedical engineering graduate students: first author James Rieffel, an MS candidate; Shuai Shao, a PhD candidate; and Upendra Chitgupi, an MS candidate.
The research team also included additional collaborators from the UB ILPB and the Harbin Institute, as well as the University of Wisconsin and POSTECH in South Korea.