Light-up peptides could prevent nerve damage in surgery

Of all the possible unintended consequences of surgery, among the most frightening is accidental damage to thin or buried nerves. The results can range from chronic pain to permanent paralysis. Scientists at the University of California San Diego School of Medicine may have found a solution: Light 'em up. Injectable fluorescent peptides can cause hard-to-see peripheral nerves to glow, alerting surgeons to their location even before they are encountered.

Nerve preservation is important in almost every kind of surgery, but it can be challenging, said Quyen Nguyen, the study's corresponding author, in a news release. "For example, if the nerves are invaded by a tumor. Or, if surgery is required in the setting of trauma or infection, the affected nerves might not look as they normally would, or their location may be distorted."

Nguyen and colleagues at the Moores Cancer Center developed and injected a systemic, fluorescently labeled peptide, a protein fragment consisting of amino acids, into mice. The peptide preferentially binds to peripheral nerve tissue, creating a contrast from adjacent non-nerve tissues. The effect occurs within two hours and lasts for six to eight hours, with no observable effect upon the activity of the fluorescent nerves or behavior of the animals.

"Of course, we have yet to test the peptide in patients, but we have shown that the fluorescent probe also labels nerves in human tissue samples," Nguyen said. Also, fluorescence labeling occurs even in nerves that have been damaged or severed, provided they retain a blood supply. The discovery suggests fluorescence labeling might be a useful tool in future surgeries to repair injured nerves.

- read the UCSD release
- and the abstract in Nature Biotechnology