A small-molecule dye for NIR-II imaging

Nat Mater. 2016 Feb;15(2):235-42. doi: 10.1038/nmat4476. Epub 2015 Nov 23.


Fluorescent imaging of biological systems in the second near-infrared window (NIR-II) can probe tissue at centimetre depths and achieve micrometre-scale resolution at depths of millimetres. Unfortunately, all current NIR-II fluorophores are excreted slowly and are largely retained within the reticuloendothelial system, making clinical translation nearly impossible. Here, we report a rapidly excreted NIR-II fluorophore (∼90% excreted through the kidneys within 24 h) based on a synthetic 970-Da organic molecule (CH1055). The fluorophore outperformed indocyanine green (ICG)-a clinically approved NIR-I dye-in resolving mouse lymphatic vasculature and sentinel lymphatic mapping near a tumour. High levels of uptake of PEGylated-CH1055 dye were observed in brain tumours in mice, suggesting that the dye was detected at a depth of ∼4 mm. The CH1055 dye also allowed targeted molecular imaging of tumours in vivo when conjugated with anti-EGFR Affibody. Moreover, a superior tumour-to-background signal ratio allowed precise image-guided tumour-removal surgery.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Benzopyrans / chemistry
  • Benzopyrans / pharmacology*
  • Benzopyrans / urine
  • Carcinoma, Squamous Cell / pathology*
  • Cell Line, Tumor
  • Diagnostic Imaging / methods
  • Female
  • Fluorescent Dyes / pharmacology*
  • Humans
  • Indoles / chemistry
  • Indoles / pharmacology*
  • Indoles / urine
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Neoplasms, Experimental / pathology*
  • Phenylpropionates / pharmacology*
  • Spectroscopy, Near-Infrared
  • Thiadiazoles / pharmacology*


  • Benzopyrans
  • CH1055
  • DY 630
  • Fluorescent Dyes
  • Indoles
  • Phenylpropionates
  • Thiadiazoles