Potential of Polycaprolactone Nanofiber Scaffold for Ex Vivo Expansion of Cord Blood-Derived CD34+ Hematopoietic Stem Cells

Background: An efficient and practical ex vivo expansion of cord blood hematopoietic stem cells as an alternative source of HSC transplantation is crucial in understanding the potential of HSC transplantation in treating or supportive therapy in a variety of hematologic and non-hematologic disorders. The aim of this study was an ex vivo expansion of cord blood hematopoietic stem cells in a novel threedimensional polycaprolactone nanofiber scaffold coated with collagen. Methods: After 10-day cultured of cord blood CD34+ cells in 2-Dimensional and 3-Dimensional culture system, the evaluation was performed by qRT-PCR, flow cytometry and clonogenicity. Results: 3-Dimensional Polycaprolactone nano-scaffold coated with collagen provided higher total nucleated cells (50-fold vs. 38-fold) and CD34+ cells (20-fold vs. 2.6-fold) (p < 0.05) and compared to 2-Dimensional cell culture and before expansion had higher expression of homing and self-renewal genes and for VLA-4, hTERT and BMI-1 genes were statically significant (p = 0.0001). The expression of myeloid markers in 3-Dimensional scaffold was significantly higher than the 2-Dimensional culture system (p < 0.05). The total colony in 2-Dimensional culture was lower than 3-Dimensional culture medium (p < 0.05). Conclusion: This study demonstrated the synergistic effect between the three-dimensionality of the scaffold and collagen as an extracellular matrix protein, and the potential of this 3-Dimensional Polycaprolactone nanofiber scaffold coated with collagen for ex vivo expansion of HSCs.