Purpose: The near-infrared fluorescence dye Cy754 was combined with Rituximab to prepare a stronger fluorescence receptor-targeted tracer for sentinel lymph node (SLN). The biological property and safety limitation was tested, and the SLN imaging ability of the new tracer was evaluated.
Materials and methods: The stronger fluorescence tracer Cy754 was combined directly with Rituximab to prepare Cy754-Rituximab. After centrifugation and purifying, the labeled rate was analyzed by instant thin-layer chromatography-silica gel, the molecular integrity was tested by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the molecular immune activity was tested by ELLAS. After the acute toxicity and the local toxicity tested, the SLN localization ability of the tracer was evaluated in the SLN animal model and compared with ICG, ICG-Rit, and radiotracer.
Results: Rituximab was intact and kept the immune activity in Cy754-Rituximab. The Cy754 labeled rate of Rituximab was 100%. The fluorescent intensity of Cy754-Rit was 0.8×1010, ICG-Ritwas 0.2×1010. The stronger fluorescence-targeted tracer was no bacteria and pyogen, and was no toxicity to mice with local injection. After Cy754-Rituximab injection, the fluorescence imaging SLN could find in the SLN animal model. The location of SLN identified by Cy754-Rituximab was accorded with the standard radiotracer. The depth of fluorescence penetration was about 1.5 cm.
Conclusions: The Cy754-Rituximab is a stronger fluorescence receptor-targeted tracer for SLN, which has a simple, effective, and no radioactive burden produce progress.