Comparative effects of selenium compounds on human umbilical cord mesenchymal stem cell expansion

Cell culture media specifically formulated to promote the growth of mesenchymal stem cells (MSCs) are essential for the clinical application of these cells. The biological effects of selenium on MSCs are related to its form, but it is not yet determined which form of selenium is more effective for the cultivation of MSCs. This study evaluated the effects of four selenium compounds-selenocysteine (SeCys), sodium selenite (Na₂SeO₃), lentinan-functionalized selenium nanoparticles (LET-SeNPs), and polyethylene glycol-modified selenium nanoparticles (PEG-SeNPs)-on the proliferation and oxidative stress of human umbilical cord MSCs (hUC-MSCs). Under the tested conditions, PEG-SeNPs (4 μM) and Na₂SeO₃ (0.25 μM) exhibited greater proliferation-promoting effects than SeCys and LET-SeNPs. Morphological analysis and flow cytometry confirmed that both PEG-SeNPs and Na₂SeO₃ preserved the cellular morphology and phenotypic identity of MSCs. Notably, flow cytometry also revealed that PEG-SeNPs reduced intracellular reactive oxygen species levels compared to the control group. Collectively, both PEG-SeNPs and Na₂SeO₃ enhance MSC proliferation, suggesting their utility for optimizing hUC-MSCs expansion culture, with PEG-SeNPs additionally providing antioxidant benefits.