Method Makes PET Tracers Out of Common Biomolecules

Researchers from the University of North Carolina Lineberger Comprehensive Cancer Center have developed new radioactive tracers to track pharmaceuticals in the body and to image cancer. The findings, reported in journal Science, describe the new chemistry they have developed, along with data that demonstrate that the team was able to radioactively tag compounds that have been very difficult, or impossible, to label to date. This method could help advance medical imaging technology and provide additional information when studying pharmaceuticals and cancer.

Typically, radioactive molecules are needed for positron emission tomography, or PET imaging. The imaging technique works by administering a radioactive substance and monitoring the distribution of the radioactive signal in the body. Different compounds that are injected can be used to study different aspects of physiology or disease. Only a handful of radioactive compounds are actually available, which limits the potential applications of PET. This new work demonstrates a chemical technique of adding a radioactive fluorine atom into all kinds of biomolecules, which could allow for monitoring of the spread of disease, where drug molecules are flowing, and a whole host of other possibilities.

The technique works by first breaking a specific chemical structure of carbon and hydrogen atoms using a blue laser and a catalyst. The researchers then insert radioactive atom fluorine-18, which was created by using a particle accelerator, into the molecule. The fluorine-18 undergoes radiodecay, and that signal can be picked up by the PET. The researchers say the next step is to develop a device that would make it easier for scientists to create these tracers on their own.

“Positron emission tomography is a powerful and rapidly developing technology that plays key roles in medical imaging as well as in drug discovery and development,” in a published statement said the study’s co-corresponding author, UNC Lineberger’s Zibo Li, PhD, an associate professor in the UNC School of Medicine Department of Radiology. “This discovery opens a new window for generating novel PET agents from existing drugs.”

The paper in Science: Direct arene C–H fluorination with 18F− via organic photoredox catalysis

Via: UNC