Enhancing ex vivo expansion of cord blood-derived unrestricted somatic stem cells for clinical applications

Cell Prolif. 2013 Dec;46(6):628-36. doi: 10.1111/cpr.12070.


Objectives: To study effects of serum-containing medium (SCM) versus serum-free medium (SFM) and influence of seeding density, on rate of expansion of cord blood (CB) unrestricted somatic stem cells (USSCs), as a prerequisite for evaluating their therapeutic potential in ongoing clinical trials.

Material and methods: Isolation, propagation and characterization of USSCs from CB samples were performed and followed by their passage 3 culture in SCM and SFM, at cell densities of 5, 50, 500 and 5000 cells/cm(2) .

Results: The cells were CD44(+) , CD90(+) , CD73(+) , CD105(+) , CD34(-) , CD45(-) , and HLA-DR, with Oct4 & Sox2 gene expression; they were differentiated into osteoblasts and adipocytes. USSCs cultured in SCM had significantly higher population doubling levels (P < 0.01) than those cultured in SFM. Those cultured in SCM at 5 cells/cm(2) and those cultured in SFM at 50 cells/cm(2) had significantly higher population doubling (P < 0.01) levels than those cultured at higher cell densities.

Conclusions: For scaling up of USSCs from 106 (?) to 1012 (?) in 6 weeks, culturing of CB-derived cells of early passage (≤P3) in SCM at low cell seeding density (5 cells/cm(2) ) is suggested for increasing cell count with lower passaging frequency, followed by culture of expanded USSCs at 50 cells/cm(2) in SFM, to avoid undesirable effects of bovine serum in clinical applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Culture Techniques / methods
  • Cell Differentiation / physiology
  • Cell Proliferation
  • Culture Media / metabolism
  • Culture Media, Serum-Free / metabolism
  • Fetal Blood / cytology*
  • Fetal Blood / metabolism
  • Fetal Blood / physiology*
  • Humans
  • Serum / metabolism
  • Stem Cells / cytology*
  • Stem Cells / metabolism
  • Stem Cells / physiology*


  • Culture Media
  • Culture Media, Serum-Free