Analysis On Expansion Potentials And Pre-clinical Safeties Of Hematopoietic Stem Cells From Human Umbilical Cord Blood

Hematopoietic stem cell transplantation(HSCT)has been used in treatment of hematologic malignancies.Sufficiency of hematopoietic/ progenitor stem cells(HS/PCs)is critical for successful transplantation. HS/PCs from human umbilical cord blood were co-cultured with bone marrow-derived mesenchymal stem cells(BM-MSCs)as a feeder layer.After co-culture for 10 days,the total nuclear cells(TNCs)increased 75-fold,and CD34~+ cells increased 33-fold.The granulocyte-macrophage colony-forming cells(GM-CFCs)and erythroid colony-forming cells(E-CFCs)increased 3.3-and 4.7-folds respectively.The expanded cells were collected and prepared as the expanded HS/PCs product with a density of 1×10~7 cells/ml by re-suspending cells in L-15 Medium.For pre-clinical safety,the expanded HS/PCs product was determined the contamination of bacteria,fungi and mycoplasmas,the bacterial endotoxin concentration,the BSA content and the SCF content.The results showed that the expanded HS/PCs product was contaminated no bacteria,fungi and mycoplasmas.The bacterial endotoxin concentration is less than the limitation of 6EU/ml,BSA residual 18.2ng/ml and SCF residual is 75pg/ml.For the clinical safety,the expanded HS/PCs product is qualified for clinical transplantation.Finally,the expanded HS/PCs product was transplanted into the immuno-deficient mice.The transplantation experiment demonstrated that the expanded HS/PCs product could not damage the organs of immuno-deficient mice and could not cause any tumor.