Fluorescence labeling of a Na(V)1.7-targeted peptide for near-infrared nerve visualization

BACKGROUND: Accidental peripheral nerve injury during surgical intervention results in a broad spectrum of potentially debilitating side effects. Tissue distortion and poor visibility can significantly increase the risk of nerve injury with long-lasting consequences for the patient. We developed and characterized Hs1a-FL, a fluorescent near-infrared molecule for nerve visualization in the operating theater with the aim of helping physicians to visualize nerves during surgery. Hs1a was derived from the venom of the Chinese bird spider, Haplopelma schmidti, and conjugated to Cy7.5 dye. Hs1a-FL was injected intravenously in mice, and harvested nerves were imaged microscopically and with epifluorescence. RESULTS: Hs1a-FL showed specific and stable binding to the sodium channel Na(V)1.7, present on the surface of human and mouse nerves. Hs1a-FL allowed epifluorescence visualization of sciatic mouse nerves with favorable nerve-to-muscle contrast. CONCLUSIONS: Fluorescent Na(V)1.7-targeted tracers have the potential to be adopted clinically for the intraoperative visualization of peripheral nerves during surgery, providing guidance for the surgeon and potentially improving the standard of care.