Expansion of human cord blood hematopoietic stem/progenitor cells in three-dimensional Nanoscaffold coated with Fibronectin

BACKGROUND Allogeneic hematopoietic stem cell transplantation is used in the treatment of patients suffering from hematologic and non-hematologic disorders, but the application is limited by the identification of a suitable donor. Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cell (HSC) transplantation. Despite all advantages, the limited cell dose is one of the  major obstacles. Ex-vivo expansion of HSC is an alternative way to overcome this problem. MATERIALS AND METHODS In this study, polycaprolactone (PCL) scaffold coated with fibronectin (3D) is compared to routine cell culture system (two dimensional, 2D) used for cell culture.1×10(4) cord blood CD34+ cells isolated by MACS were seeded on PCL scaffold and allowed to expand for 10  days. Before and after this period, total cells, CD34(+) cells, CFC assay and CXCR4 expression were evaluated. RESULTS Our findings demonstrated that 3D scaffold produced a 58-fold expansion of total cells compared to 2D cultures (38-fold expansion). Also CD34+ cells in 3D compare to 2D cell culture was 40-fold and 2.66 fold increased, respectively; this difference was statistically significant (p<0.05). Moreover, total number of colonies in the 3D scaffold was higher than those of 2D cell culture system, but no statistically significant difference was observed. Higher expression of CXCR4 in 3D compared to 2D showed better homing of cells that were cultured in 3D scaffold (p<0.05). CONCLUSION PCL scaffold coated with fibronectin had higher number of total cells and CD34+cells than 2D routine culture system. Findings revealed that 3D is a proper cell culture system for hematopoietic stem cell expansion, compared to 2D.