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 NaV1.7, 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 NaV1.7-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.
The monitoring of lymphatic drainage is of great importance, particularly in the context of the early detection and diagnosis of several diseases. Existing methods of imaging and monitoring lymphatic drainage can be costly and require trained personnel, posing problems for at-home or point-of-care monitoring. Recently, an alternative approach has been proposed, consisting of using microneedles to deliver a near-infrared (NIR) fluorescent tattoo to the skin, which can be monitored with traditional laboratory-based fluorescence detectors. In this work, we present further development of this approach, using a specifically designed NIR-fluorescent probe and rational optimization of microneedle properties and the spatial location of the NIR dye within the microneedles. Moreover, we demonstrate that this method is compatible with a custom-made portable fluorescence measurement device and able to discriminate between drainage and lack of drainage in vivo in rats.
