In vivo and in situ real-time fluorescence imaging of peripheral nerves in the NIR-II window

The peripheral nervous system(PNS)is essential for performing and maintaining various motor and sensory functions.Abnormalities can lead to a series of peripheral neurological conditions,such as paraesthesia,pain,or spasms,which are debilitating and lowering the quality of life.Thecurrent guidelines for diagnosis rely predominantly on clinical symptoms resulting from PNS dysfunction,which occur already at an advancedstage.There are currently no effective methods that visually reflect the extent of peripheral neuropathy.In our study,we present a novel in vivoand in situ real-time imaging of peripheral nerves based on the second near-infrared window(NIR-II)fluoresce nee.In NIR-II system,lead sulfidequa ntum dots(PbS Qds)with NIR-II fluoresce nee specifically bound to motor neuro rvspecific protein agrin,acting as image con trast.In micemodel,peripheral nerves were visible as soon as after 2 h post injection.We provide evidenee for the efficacy of this approach,which allows todirectly dem on strate peripheral nerves,their structure,and pote ntial damagesites and degree.Furthermore,our products were of goodbiocompatibility,while the n eural fluoresce nee signal was solid,bright and stable for 4 h in vivo.Thus,overall,our results suggest that NIR-II isan effective new method for direct imaging of peripheral nerves in vivo,opening new horizons on early,improved and more precise,targeteddiag no sis.A resulti ng more rapid installatio n of perso nalized therapy facilitates a better prognosis of clinical peripheral neuropathy.