Harvest Of Stem Cells Derived From Umbilical Cord Blood

Umbilical cord blood(UCB) contains both hematopoietic stem cells(HSCs) and mesenchymal stem cells(MSCs).HSCs have been used for gene therapy,tumor depollution and hematopoiesis reconstitution.UCB-MSCs as another type of stem cells in UCB,can not only support the expansion of HSCs in vitro as stromal cells but also alleviate complications and accelerate recovery of hematopoiesis during hematopoietic stem cell transplantation. Therefor,co-culturing HSCs and MSCs derived from human UCB is useful for clinical applications.In this study microcarriers were applied to provide surface for UCB-MSCs to adhere during the co-culture.First,we designed an orthogonal experiment to analyze the factors influncing the adhering of UCB-MSCs,including the addition of serum,the addition of cytokine and the type of microcarrier.It was demonstrated that serum is the important factor for the adhering of UCB-MSCs.Then considering the safety of clinical applications,we tried to use autoserum from UCB to replace fetal bovine serum.It was verified that the autoserum had the same effect as the FBS. And both the UCB-HSCs and UCB-MSCs can be harvested simultaneously after the culture. In addition,the two kinds of stem cells can be separated easily with sedimentation after the co-culture because of the distinct size difference between cytodex-3 microcarrier and suspended HSCs.And the probability of culture UCB-MSCs with autoserm was about 71.4%.Lastly,we investigated if the concentration of autoserum can influnce the expansion of UCB-MSCs and UCB-HSCs.Four concentrations,2.8%,5.6%,8.3%and 11.1%were selected.The results indicated that the expansions of UCB-HSCs cultured with 5.6% autoserum is 1.88±0.33 folds,better than others.And the concertrantion had little effect on the expansion of UCB-MSCs.So 5.6%autoserum is the optimization concertrantion for co-culture UCB-HSCs and UCB-MSCs.