Anti-P0 Antibody-Conjugated Nanoscale Contrast Agent Targeting the Myelin Sheath for Intraoperative Visible Delineation of Cranial Nerves

The preservation of cranial nerves is a major problem that surgeons encounter when resecting a tumor in the posterior cranial fossa. Most cranial nerve injuries occur because the tight adhesion between the tumor capsule and cranial nerves renders the nerves indistinguishable. In this study, a nerve-specific nanoscale contrast agent was developed for visually distinguishing cranial nerves from the tumor surface in real time. To enable the contrast agent to specifically bind peripheral nerves, a previously reported biodegradable multiblock polyurethane nanoparticle (BMPU NP) was conjugated with an antibody against myelin protein zero (MPZ, P0), which is expressed on myelin sheaths in peripheral nerve fibers. Coomassie brilliant blue G (CB) was encapsulated into the BMPU NP for visual contrast. The CB-BMPU NP specifically stained mouse peripheral nerve fibers blue when directly applied to the nerve surface ex vivo and in vivo. The CB-BMPU NP also achieved satisfactory visual contrast of the trigeminal nerve in a mouse nerve-tissue adhesion model. This study offers new insights for the development of intraoperatively applied nerve-specific contrast agents for delineating cranial nerves adhered to tumors.