Radiolabeled mannosylated dextran derivatives bearing an NIR-fluorophore for sentinel lymph node imaging

Bioconjug Chem. 2014 Nov 19;25(11):1963-70. doi: 10.1021/bc500336a. Epub 2014 Oct 14.

Abstract

Current methods for sentinel lymph node (SLN) mapping involve the use of radioactivity detection with technetium-99m sulfur colloid and/or visually guided identification using a blue dye. To overcome the kinetic variations of two individual imaging agents through the lymphatic system, we report herein on two multifunctional macromolecules, 5a and 6a, that contain a radionuclide ((99m)Tc or (68)Ga) and a near-infrared (NIR) reporter for pre- and/or intraoperative SLN mapping by nuclear and NIR optical imaging techniques. Both bimodal probes are dextran-based polymers (10 kDa) functionalized with pyrazole-diamine (Pz) or 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelating units for labeling with fac-[(99m)Tc(CO)3](+) or (68)Ga(III), respectively, mannose units for receptor targeting, and NIR fluorophore units for optical imaging. The probes allowed a clear visualization of the popliteal node by single-photon emission computed tomography (SPECT/CT) or positron emission tomography (PET/CT), as well as real-time optically guided excision. Biodistribution studies confirmed that both macromolecules present a significant accumulation in the popliteal node (5a: 3.87 ± 0.63% IA/organ; 6a: 1.04 ± 0.26% IA/organ), with minimal spread to other organs. The multifunctional nanoplatforms display a popliteal extraction efficiency >90%, highlighting their potential to be further explored as dual imaging agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dextrans / chemistry*
  • Dextrans / pharmacokinetics
  • Female
  • Gallium Radioisotopes
  • Infrared Rays*
  • Intraoperative Period
  • Isotope Labeling
  • Lymph Nodes / diagnostic imaging*
  • Lymph Nodes / surgery
  • Mannose / chemistry*
  • Optical Imaging / methods*
  • Radiography
  • Radionuclide Imaging
  • Rats
  • Rats, Wistar

Substances

  • Dextrans
  • Gallium Radioisotopes
  • Mannose