Comparing the growth kinetics and characteristics of Wharton's jelly derived mesenchymal stem cells expanded using different culture mediums.

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) can be isolated from umbilical cords which is abundant and easy to obtain. Due to their potent immunosuppressive properties, multilineage differentiation potential, and lack of ethical issues, WJ-MSCs are considered a promising candidate for therapeutic applications. However, large-scale in vitro expansion is necessary to obtain enough cells for therapeutic purposes. Therefore, this study aimed to optimize cell culture conditions and determine the characteristics of expanded WJ-MSCs. WJ-MSCs were seeded in 6-well plates at a density of 5000 cells/cm² and cultured with different mediums, including DMEM-LG+10% FBS, DMEM-LG+10% HPL, serum-free commercial medium 1, serum-free GMP grade commercial medium 2, and HPL supplemented commercial medium 3. The cell morphology and growth kinetics were compared, and the three most suitable mediums were selected for further experiments. WJ-MSCs were then cultured in the selected mediums at seeding densities ranging from 1000 to 5000 cells/cm², and cell growth kinetics were analysed. WJ-MSCs cultured in the selected mediums were characterized by their immunophenotype, tri-lineage differentiation potential and immunosuppression property. WJ-MSCs cultured with DMEM-LG+10% HPL, commercial medium 1 and commercial medium 2 showed smaller size, significantly higher cell yield, and shorter population doubling time than those cultured in other mediums. Hence, these three mediums were selected for further experiments. Only DMEM-LG + 10% HPL medium maintained high cell yields (1.48 ± 0.14 × 10⁶ with bFGF and 1.56 ± 0.17 × 10⁶ without bFGF) at the lowest seeding density tested. However, WJ-MSCs cultured in all three mediums expressed the MSC surface markers, were able to suppress PBMC proliferation, and could differentiate into adipogenic, chondrogenic and osteogenic lineages. In summary, DMEM-LG+10% HPL is the best medium for WJ-MSC expansion, as it provides the highest cell yield without compromising cell characteristics and functionality. The potential of this medium for large-scale expansion using a bioreactor or multilayered flask should be investigated in the future.