BACKGROUND:Preliminary data showed that the application of human platelet lysate to human umbilical cord mesenchymal stem cell culture can better maintain the characteristics of stem cells than the application of serum-free medium. However, the serum-free medium can better improve the proliferation of mesenchymal stem cells in vitro than the human platelet lysate.OBJECTIVE:To screen out a better mesenchymal stem cell cultivation system that can greatly maintain the characteristics and proliferation rate of human umbilical cord mesenchymal stem cells.METHODS:Six human umbilical cord specimens were inoculated in six culture systems, and the primary culture of umbilical cord mesenchymal stem cell was performed. These six culture systems were respectively MesenCult serum-free medium with 2% human platelet lysate (group A), StemPro serum-free medium with 2% human platelet lysate (group B), MesenCult serum-free medium (group C), StemPro serum-free medium (group D), low glucose-DMEM with 10% fetal bovine serum (group E), low glucose-DMEM with 10% human platelet lysate (group F). The cells were subcultured at 14 days after inoculation to compare the effects of different culture systems on the morphology, surface markers, differentiation and proliferation of human umbilical cord mesenchymal stem cells.RESULTS AND CONCLUSION:(1) The morphology of passage 3 cells in group D was elongated and uneven in size. The morphology of passage 3 cells was flattened in groups E and F, but the cells in the other groups were spindle-shaped and uniform. There were no significant changes in morphology and size between passage 3 and 5 cells in A and B. In group C, the morphology of passage 5 cells was more flattened and uneven in size compared with passage 3 cells. In group D, the morphology of passage 5 cells was more elongated than that of passage 3 cell. In group E, the morphology of passage 5 cells was more flattened than that of passage 3 cells. There was no significant difference in morphology between passage 3 and 5 cells in group F. (2) The expression rate of cell surface markers had no significant difference at different passages in each group. (3) The adipoinduction and osteoinduction rates were relatively higher in groups A and B compared with groups E and F, and lowest in groups C and D. (4) The cell proliferation rate for each passages in group A was significantly higher than that in group C. The cell proliferation rate for each passage in group B was significantly higher than that in group D. The cell proliferation rate for each passage in groups E and F was significantly lower than that in groups A and B. To conclude, these results suggest that the combination of serum-free medium with human platelet lysate could better maintain the characteristics and the proliferation efficiency of mesenchymal stem cells.