Visualization of Sentinel Lymph Nodes with Mannosylated Fluorescent Nanodiamonds

The present study focuses on the development of a sensitive and specific approach for the visualization of sentinel lymph nodes draining the tumor using ultrabright 200-nm fluorescent nanodiamonds (FNDs) equipped with a designed targeting surface architecture. The FNDs with a narrow size distribution are isolated by differential centrifugation, colloidally stabilized with alkyne-functionalized poly(glycerol) and modified with a polyvalent array of mannose (FND-p-Man). In vitro experiments demonstrate an outstanding increase of the particle internalization by the mannose receptor CD206 (MR) and no significant toxicity. MR involvement is confirmed by blocking ligand binding with mannan and a 15.2 mAb (specific anti-MR) in J774A.1 mouse macrophage cell line. In vivo mouse experiments confirm increased retention of FND-p-Man in sentinel lymph nodes of both healthy and B16 melanoma bearing animals. These results suggest that FND-p-Man has potential as a tracer for lymph node visualization in locoregional perioperative cancer diagnostics and as a tool for endoscopic/robotic fluorescence-guided surgery.

Automated summary

This study developed a sensitive approach using fluorescent nanodiamonds for visualizing tumor-draining sentinel lymph nodes. The results showed that the modified nanodiamonds have potential as a tracer for cancer diagnostics and fluorescence-guided surgery.