Fluorescent microparticles for sensing cell microenvironment oxygen levels within 3D scaffolds

Biomaterials. 2009 Jun;30(17):3068-74. doi: 10.1016/j.biomaterials.2009.02.021. Epub 2009 Mar 14.


We present the development and characterization of fluorescent oxygen-sensing microparticles designed for measuring oxygen concentration in microenvironments existing within standard cell culture and transparent three-dimensional (3D) cell scaffolds. The microparticle synthesis employs poly(dimethylsiloxane) to encapsulate silica gel particles bound with an oxygen-sensitive luminophore as well as a reference or normalization fluorophore that is insensitive to oxygen. We developed a rapid, automated and non-invasive sensor analysis method based on fluorescence microscopy to measure oxygen concentration in a hydrogel scaffold. We demonstrate that the microparticles are non-cytotoxic and that their response is comparable to that of a traditional dissolved oxygen meter. Microparticle size (5-40 microm) was selected for microscale-mapping of oxygen concentration to allow measurements local to individual cells. Two methods of calibration were evaluated and revealed that the sensor system enables characterization of a range of hypoxic to hyperoxic conditions relevant to cell and tissue biology (i.e., pO(2) 10-160 mmHg). The calibration analysis also revealed that the microparticles have a high fraction of quenched luminophore (0.90+/-0.02), indicating that the reported approach provides significant advantages for sensor performance. This study thus reports a versatile oxygen-sensing technology that enables future correlations of local oxygen concentration with individual cell response in cultured engineered tissues.

Publication types

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

MeSH terms

  • Biocompatible Materials / chemistry
  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods
  • Calibration
  • Cell Culture Techniques / instrumentation*
  • Cells, Cultured
  • Dimethylpolysiloxanes / chemistry
  • Fluorescent Dyes / metabolism
  • Microscopy, Fluorescence
  • Microspheres*
  • Oxygen / analysis*
  • Oxygen / metabolism
  • Particle Size
  • Tissue Engineering
  • Tissue Scaffolds*


  • Biocompatible Materials
  • Dimethylpolysiloxanes
  • Fluorescent Dyes
  • baysilon
  • Oxygen