Human umbilical cord mesenchymal stem cells:Comparison of hematopoiesis supporting capacity before and after cryopreservation / 中国组织工程研究

ABSTRACT

BACKGROUND:Cryopreservation of human umbilical cord mesenchymal stem cel s has been a hot research issue currently, but the studies concerning their effects on expansion of hematopoietic stem/progenitor cel s after cryopreservation are seldom. OBJECTIVE:To investigate the effects of human umbilical cord mesenchymal stem cel s before and after cryopreservation as feeder layer on expansion of human bone marrow mononuclear cel s in vitro. METHODS:2.5g/L mitomycin C processed human umbilical cord mesenchymal stem cel s and bone marrow mesenchymal stem cel s at passage 3 were used as the feeder layer to expand adult al ogeneic bone marrow mononuclear cel s in culture. Up to day 35, methylcel ulose assay was used to detect hematopoietic stem/progenitor cel colony proliferation. RESULTS AND CONCLUSION:There were no differences in the morphology and size of colonies in the cryopreserved human umbilical cord mesenchymal stem cel group, bone marrow mesenchymal stem cel group and non-cryopreserved human umbilical cord mesenchymal stem cel group. However, these parameter described above were significantly higher in these three groups than the blank control group (P<0.05). There were fewer colonies in the cryopreserved human umbilical cord mesenchymal stem cel group than the non-cryopreserved human umbilical cord mesenchymal stem cel group (P<0.05). These findings indicate that human umbilical cord mesenchymal stem cel s before and after cryopreservation have the ability as feeder layer on expansion of bone marrow mononuclear cel s in vitro similar to bone marrow mesenchymal stem cel s. But this ability of human umbilical cord mesenchymal stem cel s may decrease after cryopreservation.