Phosphorescent nanoparticles for quantitative measurements of oxygen profiles in vitro and in vivo

Biomaterials. 2012 Mar;33(9):2710-22. doi: 10.1016/j.biomaterials.2011.11.048. Epub 2012 Jan 10.


We present the development and characterization of nanoparticles loaded with a custom phosphor; we exploit these nanoparticles to perform quantitative measurements of the concentration of oxygen within three-dimensional (3-D) tissue cultures in vitro and blood vessels in vivo. We synthesized a customized ruthenium (Ru)-phosphor and incorporated it into polymeric nanoparticles via self-assembly. We demonstrate that the encapsulated phosphor is non-toxic with and without illumination. We evaluated two distinct modes of employing the phosphorescent nanoparticles for the measurement of concentrations of oxygen: 1) in vitro, in a 3-D microfluidic tumor model via ratiometric measurements of intensity with an oxygen-insensitive fluorophore as a reference, and 2) in vivo, in mouse vasculature using measurements of phosphorescence lifetime. With both methods, we demonstrated micrometer-scale resolution and absolute calibration to the dissolved oxygen concentration. Based on the ease and customizability of the synthesis of the nanoparticles and the flexibility of their application, these oxygen-sensing polymeric nanoparticles will find a natural home in a range of biological applications, benefiting studies of physiological as well as pathological processes in which oxygen availability and concentration play a critical role.

Publication types

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

MeSH terms

  • Animals
  • Biocompatible Materials / pharmacology
  • Calibration
  • Cell Death / drug effects
  • Cell Line, Tumor
  • Female
  • Humans
  • Imaging, Three-Dimensional
  • Light
  • Luminescent Measurements / methods*
  • Mice
  • Microfluidics
  • Models, Biological
  • Nanoparticles / chemistry*
  • Oxygen / metabolism*
  • Particle Size
  • Scattering, Radiation
  • Spectrophotometry, Ultraviolet


  • Biocompatible Materials
  • Oxygen