Nerve-targeted probes for fluorescence-guided intraoperative imaging

Abstract

A fundamental goal of many surgeries is nerve preservation, as inadvertent injury can lead to patient morbidity including numbness, pain, localized paralysis and incontinence. Nerve identification during surgery relies on multiple parameters including anatomy, texture, color and relationship to surrounding structures using white light illumination. We propose that fluorescent labeling of nerves can enhance the contrast between nerves and adjacent tissue during surgery which may lead to improved outcomes.Methods: Nerve binding peptide sequences including HNP401 were identified by phage display using selective binding to dissected nerve tissue. Peptide dye conjugates including FAM-HNP401 and structural variants were synthesized and screened for nerve binding after topical application on fresh rodent and human tissue and in-vivo after systemic IV administration into both mice and rats. Nerve to muscle contrast was quantified by measuring fluorescent intensity after topical or systemic administration of peptide dye conjugate.Results: Peptide dye conjugate FAM-HNP401 showed selective binding to human sural nerve with 10.9x fluorescence signal intensity (1374.44 ± 425.96) compared to a previously identified peptide FAM-NP41 (126.17 ± 61.03). FAM-HNP401 showed nerve-to-muscle contrast of 3.03 ± 0.57. FAM-HNP401 binds and highlight multiple human peripheral nerves including lower leg sural, upper arm medial antebrachial as well as autonomic nerves isolated from human prostate.Conclusion: Phage display has identified a novel peptide that selectively binds to ex-vivo human nerves and in-vivo using rodent models. FAM-HNP401 or an optimized variant could be translated for use in a clinical setting for intraoperative identification of human nerves to improve visualization and potentially decrease the incidence of intra-surgical nerve injury.

Fluorescence background quenching as a means to increase Signal to Background ratio - a proof of concept during Nerve Imaging

“…While the fluorescence deactivation concept may also prove of value during systemic applications, it is likely to hold most promise in procedures were local tracer deposition is being used. Next to experimental nerve imaging 31 , 32 , this could e.g. be embolization strategies 33 , or sentinel lymph node procedures 6 .…”

Advanced Nanotechnology Leading the Way to Multimodal Imaging‐Guided Precision Surgical Therapy

“…[9][10][11] This section introduces the mechanisms and methods through which NP systems reach surgical target regions, thereby helping operations achieve the abovementioned requirements. and the prevention of damage to nearby structures, such as important vessels, nerves, and organs.…”

Sight and switch off: Nerve density visualization for interventions targeting nerves in prostate cancer

“…Nerve-binding peptide, NP41, detected using a phage display method (27), preferentially binds to neural laminins in the extracellular matrix (28). NP41 has been used to highlight autonomic nerves within the prostate (29), facial nerves (30,31), vagal nerves of the esophagus and stomach (32), and degenerated nerves (28). Since PCa is innervated, NP41, with increased specificity, is potentially applicable for visualizing nerve abundance in PCa.…”