Antibody fragments expand what PET imaging can ‘see’ in mice

June 3, 2015

To visualize cancer throughout the body, physicians often turn to positron emission tomography (PET), which lights up areas that are metabolically active or growing, like tumors. Today in ACS Central Science, researchers report development of new PET probes composed of labeled antibody fragments that were tested in mice. These probes could someday be used to create targeted probes, giving doctors more information about tumors and how to treat them.

The most common PET imaging probe is a labeled sugar molecule called 18F-2-deoxyfluoroglucose (FDG). PET indicates those locations where a labeled FDG molecule ends up. Because tumor cells grow faster than healthy ones, they need more sugar to meet their energy requirements, and they consume much more of the labeled sugar probe. This makes PET ideal for seeing tumors. But this method is limited because the reporter part of the molecule, 18F, is difficult to attach to other molecules and isn’t very stable. FDG molecules are also general probes, since they can be taken up wherever the body needs energy, leading to background signals. Hidde Ploegh and coworkers set out to overcome these challenges by making probes that meet all of these needs.

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