Abstract

 Background and Objectives

 Stem cell transplantation has achieved high success for treatment but the use of this source has some limitation. Cord blood transplantation is clinically limited by its low progenitor cell contents such as CD34⁺. The aim of this study was to evaluate the effect of mesenchymal stem cells (MSCs) on replication of CD34⁺ in cord blood.

 Materials and Methods

 In this experimental study MSCs were isolated and cultured from BM mononuclear cells. MSCs were used for co-culture in two systems of 2D and 3D cultures. After isolation, umbilical cord blood CD34⁺ cells were cultured in two different systems. The level of expansion in these systems was evaluated by cell count, analysis of CD34⁺ expression by flowcytometery, and CFU assay .

 Results

 Expansion of cord blood HSCs was evaluated at three different culture systems at three different times (day3, day 7 and day 10): the medium with cytokine, 2D medium with cytokine + MSCs, and 3D medium with cytokine + MSCs on scaffold. The fold increase of TNC, CFU, and CD34⁺ cells at day 10 for the former medium was 87 ± 6, 84 ± 8, 11 ± 3, for the second 103 ± 8, 111 ± 9, 14 ± 3, and for the latter 127 ± 10, 170 ± 14, 20 ± 4, respectively. The highest expansion was observed in the 3D co-culture with MSCs after 10 days.

 Conclusions

 The results have demonstrated that the co-culture of CB HSCs with mesenchymal cells could increase the rate of expansion especially in the 3D system.