Interfacial pH and O2 evolution during molybdenum degradation for understanding cytocompatibility

Direct culturing Human Umbilical Vein Endothelial cells (HUVECs) on Mo reduced viability by ~50% from 24 to 48 h, while an equivalent Mo species maintained >80%, showing cytotoxicity stems from interfacial processes. Local analysis at Mo interface in Hanks’ solution revealed minimal pH change (0.2 unit) but severe oxygen depletion (down to 0.6 ppm) probably facilitated by MoO x . Degrading Mo markedly alters its interfacial microenvironment, likely correlating to cytocompatibility loss.