Enhancement of Mesenchymal Stem Cell Expansion by Activated Autologous Serum - Implications for Clinical Grade Expansion

  • Yeong-Hoon Choi, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany
  • Klaus Neef, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany
  • Klaus Stamm, Dept. of Cardiothoracic Surgery, German Heart Center Berlin, Germany
  • Thorsten Wittwer, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany
  • Navid Madershahian, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany
  • Oliver Liakopoulos, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany
  • Thorsten Wahlers, Dept. of Cardiothoracic Surgery, Heart Center of the University of Cologne, Germany

    • Objectives:
    Multipotent mesenchymal stem cells (MSC) from bone marrow are highly promising for emerging
    regenerative and immunomodulatory cell therapy. Due to their low frequency in bone marrow
    aspirates, in vitro expansion is mandatory. We report the use of autologous serum obtained before
    after cardiopulmonary bypass for cell culture media supplement and its effects on xeno-free, clinical
    grade expansion of MSCs.
    Methods:
    Autologous serum was prepared before and after by-pass surgery. MSC were expanded using cell
    culture media supplemented with fetal bovine serum (FBS), autologous (AS) or autologous activated
    serum (actAS). CFU-F assays, total cell count (TCC) and key stem-cell characteristics were
    determined after 3 weeks. Differences in 42 cytokine concentrations were analyzed by multiplex
    array assay.
    Results:
    MSC were successfully cultured with autologous sera. FACS analysis after 3 weeks of culture
    showed typical CD73+/CD90+/CD105+ phenotypes. All cultures retained their potential of
    differentiation into adipo-, osteo- and chondrogeneic cell lineages. CFU-F and TCC after 3 weeks
    showed superior results for actAS vs. AS or FBS, respectively (actAS: 21.7±0.5 vs. AS: 14.3±0.47,
    p<0.001; vs. FBS: 7±0.39, p<0.001). TCC (actAS vs. AS: 4fold, p<0.001; vs. FBS: 57fold,
    p<0.001). actAS vs. AS showed increased concentrations of 15 out of 42 cytokines (>5fold,
    p<0.001).
    Conclusion:
    Autologous serum is a safe and efficient component for xeno-free and clinical grade expansion of
    MSC. Endogenous factors can be exploited for enhancement of proliferation and shed light on stem
    cell activation pathways.