A comparative study on serum-free and serum culture methods of human umbilical cord mecenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Studies have shown increasing risks and problems in the serum culture system, such as immune rejection, batch differences and virus risk. In addition, with the discovery and application of exosomes, the serum-free culture system is becoming an increasing concern. OBJECTIVE: To compare the similarities and differences between the serum-free culture system and the traditional serum culture system, which lays the foundation for the clinical transformation of human umbilical cord mesenchymal stem cells (hUCMSCs) and provides experimental data. METHODS: Umbilical cord was collected from term infants of cesarean section under aseptic condition, and hUCMSCs were isolated and cultured by explant tissue technique. hUCMSCs was cultured with 10% fetal bovine serum (FBS) and 15% serum substitutes (AGS) from the original generation. Then an inverted microscope was used to observe cell morphological changes. Flow cytometry was used to detect cell surface markers. Cell counting kit-8 was used to detect cell proliferation. Induced differentiation experiment was used to detect cell differentiation potential. Western Blot was used to detect the protein levels of oct4, nanog and sox2. RESULTS AND CONCLUSION: Under the inverted microscope, hUCMSCs cultured with AGS showed more uniform vortex-like growth, and those cultured with FBS gradually appeared with cell differentiation or aging with the increase of cell generations. hUCMSCs cultured by both methods expressed CD73,CD90 and CD105 but lowly expressed CD34 and CD45, and there was no significant difference between the two culture methods. FBS method was superior to AGS method in proliferation ability. Results from the induced differentiation experiments showed that hUCMSCs cultured by both methods had adipogenic, osteogenic and chondrogenic abilities, and there was no significant difference between the two culture methods. hUCMSC cultured by both methods expressed oct4 and nanog but showed no significant difference in level, while the expression of sox2 was significantly higher in the hUCMSCs cultured by AGS than by FBS (P < 0.05). To conclude, the hUCMSCs cultured with AGS are in accordance with the international standards of mesenchymal stem cells. The AGS method as an alternative to the FBS method can become a preferred method for hUCMSCs culture.