Expansion of Cord Blood Hematopoietic Stem Cells on the Amniotic Membrane Derived Mesenchymal Stem Cells

Abstract

ABSTRACT: Because of insufficient number of umbilical cord blood hematopoietic stem cells (UCB-HSCs), expansion of these cells seems to be important for clinical application in adults. The aim of this study was to co-culture of UCB-HSCs with the amniotic membrane derived mesenchymal stem cells (AMMSCs) as a feeder layer in order to expand hematopoietic stem cells (HSCs). UCBs and amniotic membrane were collected from concern mothers. Ex vivo culture of UCB-HSCs were performed in four culture conditions: cytokine cocktail with MSCs feeder layer, cytokine cocktail, stem cell factor, and co-culture with MSCs without any cytokine. The number of total nucleated cells (TNC) was counted by hemocytometer. The HSC count and immunophenotyping of Mesenchymal stem cells (MSCs) and expanded HSC were evaluated by flow cytometry. Colony forming unit (CFU) assay was used to evaluate the potential of expanded HSCs for production of different lineage colonies. The mean fold changes of total nucleated cells (TNC) and CD34+ cells in the cytokine culture with feeder layer were higher than the cytokine culture without MSCs. However, in the co-culture system without cytokine, TNC and CD34+ cell numbers were increased up to 8 folds, but cell viability was more than 80% and differentiation rate was low. Our results demonstrated that we could increase the number of CD34+ cells of UCB that were used as primary HSC for transplantation.