Measurement of oxygen tension within mesenchymal stem cell spheroids

Kaitlin C. Murphy, Ben P. Hung, Stephen Browne-Bourne, Dejie Zhou, Jessica Yeung, Damian C Genetos, Jonathan K Leach

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Spheroids formed of mesenchymal stem cells (MSCs) exhibit increased cell survival and trophic factor secretion compared with dissociated MSCs, making them therapeutically advantageous for cell therapy. Presently, there is no consensus for the mechanism of action. Many hypothesize that spheroid formation potentiates cell function by generating a hypoxic core within spheroids of sufficiently large diameters. The purpose of this study was to experimentally determine whether a hypoxic core is generated in MSC spheroids by measuring oxygen tension in aggregates of increasing diameter and correlating oxygen tension values with cell function. MSC spheroids were formed with 15 000, 30 000 or 60 000 cells per spheroid, resulting in radii of 176+8 μm, 251+12 μm and 353+18 μm, respectively. Oxygen tension values coupled with mathematical modelling revealed a gradient that varied less than 10% from the outer diameter within the largest spheroids. Despite the modest radial variance in oxygen tension, cellular metabolism from spheroids significantly decreased as the number of cells and resultant spheroid size increased. This may be due to adaptive reductions in matrix deposition and packing density with increases in spheroid diameter, enabling spheroids to avoid the formation of a hypoxic core. Overall, these data provide evidence that the enhanced function of MSC spheroids is not oxygen mediated.

Original languageEnglish (US)
Article number20160851
JournalJournal of the Royal Society Interface
Volume14
Issue number127
DOIs
StatePublished - Feb 1 2017

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Keywords

  • Diffusion
  • Hypoxia
  • Mesenchymal stem cell
  • Oxygen tension
  • Spheroid

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biophysics
  • Biochemistry
  • Biomaterials
  • Biomedical Engineering

Cite this

Murphy, K. C., Hung, B. P., Browne-Bourne, S., Zhou, D., Yeung, J., Genetos, D. C., & Leach, J. K. (2017). Measurement of oxygen tension within mesenchymal stem cell spheroids. Journal of the Royal Society Interface, 14(127), [20160851]. https://doi.org/10.1098/rsif.2016.0851