Objective: To compare the differences of biological characteristics between human umbilical cord-derived mesenchymal stem cells (UC-MSCs) cultured by serum-free medium or fetal bovine serum-contained complete medium to establish a xenogeneic protein-free UC-MSCs culture system.
Methods: Healthy human umbilical cord segments were digested with collagenase. UC-MSCs were cultured by serum-free MesenCult-XF medium and FBS-based αMEM complete medium, then analyzed the morphology, immunophenotype, expansion potential, lineage differentiation potential, karyotype and immunosuppression of early passages.
Results: The average cell diameters of UC-MSCs in suspension cultured by serum-free medium and FBS-based medium were 26 (18 - 39) µm and 35 (20 - 61) µm, respectively. Cell expansion folds with serum free medium and FBS-based medium were (5.2 ± 0.2) and (3.5 ± 0.1) respectively, in the first five passages. The expansion potential of serum-free medium cultured UC-MSCs was significantly higher than FBS-based medium cultured ones (P < 0.05). A panel of markers CD29, CD44, CD90, CD73, CD105 and HLA-ABC expressed on human UC-MSCs. Hematopoietic lineage markers CD34, CD45 and HLA-DR were not detectable on UC-MSCs. The cpm were (4.57 ± 0.14)×10(4), (2.04 ± 0.16)×10(4) and (0.42 ± 0.04)×10(4), respectively when serum-free medium cultured MSCs were added to the cultures at MSCs/T cell ratios of 1:100, 1:10 and 1:5. While the cpm was (4.57 ± 0.14)×10(4), (2.04 ± 0.16)×10(4) and (0.42 ± 0.04)×10(4), respectively when serum-free medium cultured UC-MSCs were added to the cultures. The immunosuppressive potential of serum-free medium-cultured UC-MSCs was higher than serum-contained medium cultured ones at three different MSC/T cell ratios (P < 0.05).
Conclusion: Compare with serum-contained medium cultured early passages of UC-MSCs, the cell diameter of serum-free medium cultured UC-MSCs was smaller with higher expansion potential. No xenogeneic proteins were presented in UC-MSCs preparations when cultured with serum-free medium. Human UC-MSCs suppressed T-cell proliferation in a dose-dependent manner. The immunosuppressive potential of serum-free medium cultured UC-MSCs was higher than FBS-based medium cultured ones.