Abstract:

BACKGROUND: How to quickly improve the proliferation of human umbilical cord-derived mesenchymal stem cells as a seed cell source is an urgent problem to meet the clinical requirement for the quantity and quality.
OBJECTIVE: To explore the effects of different initial time, frequencies and volumes of perfusion on the proliferation and metabolism of human umbilical cord-derived mesenchymal stem cells and to establish a semi-continuous perfusion culture technique with high cell density.
METHODS: Human umbilical cord-derived mesenchymal stem cells were cultured and passaged, the batch cultured cells were used as control. The semi-continuous perfusion cultured cells were divided into three groups. In the initial time group: the cells were batch cultured for 24 and 48 hours, respectively, and then the media was changed for 75% every 2 days. In the perfusion frequency group: the cells were batch cultured for 48 hours, after that, the media was changed every 1, 2 and 3 days, respectively, and 75% media was changed. In the perfusion volume group: the media was changed every 2 days after batch cultured for 48 hours, 25%, 50%, 75% and 100% media was changed.
RESULTS AND CONCLUSION: The relatively higher values of dilution rate and cell density were acquired with the suitable monolayer culture of perfusion initial time at 48 hours of batch culture, and 75% (volume ratio) media exchanged every day. The higher values of glucose consumption rate, lactate formation rate and ammonia formation rate, and lower value of glutamine consumption rate were attained with higher metabolic coefficient of lactate/glucose and lower metabolic coefficient of ammonia/glutamine. It showed that with higher medium dilution, nutrients including glucose, glutamine, trace elements and other unknown factors were sufficiently supplied to meet the requirement of cell growth, and the negative effects of lactate and ammonium and the interaction effect of some factors in the culture media on the cells were relieved, leading to the enhanced proliferation of cells.

Key words: stem cells, umbilical cord/umbilical cord blood stem cells, semi-continuous perfusion culture, umbilical cord, mesenchymal stem cells, initial time, perfusion frequency, perfusion volume, amplification, metabolism, other grants-supported paper, stem cell photographs-containing paper