Fluorescent carbonaceous nanodots for noninvasive glioma imaging after angiopep-2 decoration

Bioconjug Chem. 2014 Dec 17;25(12):2252-9. doi: 10.1021/bc500474p. Epub 2014 Nov 11.

Abstract

Fluorescent carbonaceous nanodots (CDs) have attracted much attention due to their unique properties. However, their application in noninvasive imaging of diseased tissues was restricted by the short excitation/emission wavelengths and the low diseased tissue accumulation efficiency. In this study, CDs were prepared from glucose and glutamic acid with a particle size of 4 nm. Obvious emission could be observed at 600 to 700 nm when CDs were excited at around 500 nm. This property enabled CDs with capacity for deep tissue imaging with low background adsorption. Angiopep-2, a ligand which could target glioma cells, was anchored onto CDs after PEGylation. The product, An-PEG-CDs, could target C6 glioma cells with higher intensity than PEGylated CDs (PEG-CDs), and endosomes were involved in the uptake process. In vivo, An-PEG-CDs could accumulate in the glioma site at higher intensity, as the glioma/normal brain ratio for An-PEG-CDs was 1.73. The targeting effect of An-PEG-CDs was further demonstrated by receptor staining, which showed An-PEG-CDs colocalized well with the receptors expressed in glioma. In conclusion, An-PEG-CDs could be successfully used for noninvasive glioma imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Neoplasms / diagnosis*
  • Chemistry Techniques, Synthetic
  • Diagnostic Imaging / methods
  • Endosomes / metabolism
  • Fluorescent Dyes* / chemical synthesis
  • Fluorescent Dyes* / chemistry
  • Fluorescent Dyes* / pharmacokinetics
  • Glioma / diagnosis*
  • Glucose / chemistry
  • Glutamic Acid / chemistry
  • Male
  • Mice, Inbred BALB C
  • Particle Size
  • Peptides / chemistry*
  • Quantum Dots / chemistry*
  • Tissue Distribution
  • Tumor Cells, Cultured

Substances

  • Angiopep-2
  • Fluorescent Dyes
  • Peptides
  • Glutamic Acid
  • Glucose