Siloxane Nanoprobes for Labeling and Dual Modality Functional Imaging of Neural Stem Cells

Ann Biomed Eng. 2016 Mar;44(3):816-27. doi: 10.1007/s10439-015-1514-1. Epub 2015 Nov 23.


Cell therapy represents a promising therapeutic for a myriad of medical conditions, including cancer, traumatic brain injury, and cardiovascular disease among others. A thorough understanding of the efficacy and cellular dynamics of these therapies necessitates the ability to non-invasively track cells in vivo. Magnetic resonance imaging (MRI) provides a platform to track cells as a non-invasive modality with superior resolution and soft tissue contrast. We recently reported a new nanoprobe platform for cell labeling and imaging using fluorophore doped siloxane core nanoemulsions as dual modality ((1)H MRI/Fluorescence), dual-functional (oximetry/detection) nanoprobes. Here, we successfully demonstrate the labeling, dual-modality imaging, and oximetry of neural progenitor/stem cells (NPSCs) in vitro using this platform. Labeling at a concentration of 10 μL/10(4) cells with a 40%v/v polydimethylsiloxane core nanoemulsion, doped with rhodamine, had minimal effect on viability, no effect on migration, proliferation and differentiation of NPSCs and allowed for unambiguous visualization of labeled NPSCs by (1)H MR and fluorescence and local pO2 reporting by labeled NPSCs. This new approach for cell labeling with a positive contrast (1)H MR probe has the potential to improve mechanistic knowledge of current therapies, and guide the design of future cell therapies due to its clinical translatability.

Keywords: Cell-labeling; Dual-modality imaging; Fluorescence; MR oximetry; Nanoemulsions; Neural progenitor/stem cells; Polydimethylsiloxane; Rhodamine.

Publication types

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

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Movement
  • Cell Proliferation
  • Cell Tracking / methods*
  • Fluorescent Dyes* / chemistry
  • Fluorescent Dyes* / pharmacology
  • Mice
  • Molecular Imaging / methods*
  • Nanoparticles / chemistry*
  • Neural Stem Cells* / cytology
  • Neural Stem Cells* / metabolism
  • Siloxanes* / chemistry
  • Siloxanes* / pharmacology
  • Staining and Labeling / methods


  • Fluorescent Dyes
  • Siloxanes