Effect of Stemregenin1 and Sb431542 Small Molecules on Ex Vivo Expansion of Umbilical Cord Blood Hematopoietic Stem Cells on Biocompatible Polyethersulfone Nanofiber Scaffolds

Abstract

Cord  blood  Hematopoietic stem  cells  (HSCs) with several  advantages  including low  chance  of  viral contamination  and  low  rate  ofGraft  versus  host  disease  (GVHD)are  appropriate  candidate  for  vast medical applications such as transplantation. The main obstacle ofcord blood HSCs is the low number cells. To improve ex-vivo expansion of umbilical cord HSCs we introduced a new culturesystem. Isolated HSCs    were    seeded    in Three-dimensional(3D) on Polyethersulfone(PES)   scaffolds and Two-dimensional(2D) culture conditions and treated with SB431542 and Stemregenin1(SR1)small molecules. On the fifth and tenth days the expanded cells in different groups were investigatedfor expression of specific  markersby  flow  cytometry, expression  of some  stemnessgenes by qRT-PCRandcolony formation bymethocult medium. SR1 molecule significantly increased expansion of CD34+ cellswhile SB431542induced more CD34+/38+cells. AlsoSB431542 treated cells showed higher colony formation capacity. SR1 increased the expression of c-Myc, HOXB4and SALL4while SB431542 seemed to inhibit HOXB4expression and increase SALL4.Together all, this study introduced a new ex vivo culture setting for further medical application of HSCs. Our data showed simultaneous use of these two small molecules can  provide  appropriate outcome  for  HSCs  transplantation  includes  both  of  engraftment  and repopulation