Influence of lactic acid on the proliferation, metabolism, and osteogenic differentiation of mesenchymal stem cells

摘要

Mesenchymal stem cells (MSCs) may face a poor environment in high lactic acid originated from cell cultures, degradation of biomaterials, and other sources. This study aimed to determine if proliferation, metabolism, and osteogenic differentiation of MSCs were influenced by decreasing pH, increasing osmotic pressure, or chemical action of lactate ion. It was seen that the proliferation and metabolism of MSCs was inhibited in cultures with decreasing pH or high lactate.However, when osmolarity was adjusted to the same condition as that of sodium lactate using sodium chloride, it did not show the same degree of cell proliferation and metabolism influence. We also concluded that colony-forming efficiency and osteogenic differentiation were significantly depressed by low pH or high lactate. As was shown, the inhibition of lactate was not only due to osmotic pressure, but also mainly due to chemical effect of lactate ion. Thus, pH control is necessary, but not sufficient, to eliminate the influence of lactic acid on losing stem-cell characteristics of MSCs.