Dose- and time-dependent endothelial metabolic reprogramming induced by biomolecular corona-forming silica nanoparticle agglomerates.

Silica nanoparticles (SiO₂NPs) are increasingly used in biomedical and industrial applications, yet their effects on endothelial cell metabolism at the pathway level remain incompletely characterized. Here, we used 1H NMR-based metabolomics to investigate the metabolic response of human endothelial cells (HUV-EC-C) exposed to prolate SiO₂NP@biomolecule agglomerates formed spontaneously in serum-containing medium across a range of concentrations and incubation times. Exposure induced dose- and time-dependent metabolic reprogramming, characterized by increased glucose consumption and a metabolic profile consistent with increased glycolytic reliance, together with extracellular accumulation of succinate and glycolytic end-products consistent with alterations in TCA cycle-associated metabolism. Depletion of NADP+ and glutathione precursors, together with increased extracellular pyroglutamate, indicated alterations in redox-related metabolism and glutathione turnover, which were further supported by changes in intracellular reactive oxygen species levels. Additionally, reductions in phosphocholine-related metabolites and UDP-GlcNAc indicated alterations in phospholipid metabolism and protein glycosylation, while creatine-phosphocreatine depletion was consistent with impaired energy homeostasis. These metabolic alterations were accompanied by fluorescence microscopy evidence of cytoskeletal disorganization, cell shrinkage, and apoptotic-like features. Collectively, our findings identify dose- and time-dependent metabolic reprogramming in endothelial cells exposed to SiO₂NP@biomolecule agglomerates and support a working model involving alterations in glycolytic reliance, mitochondrial-associated metabolism, redox regulation, energy homeostasis, and membrane remodeling. Given that these mechanistic interpretations are primarily based on metabolomic profiles and complementary ROS measurements, further functional studies are required to establish the underlying metabolic pathways. These findings provide a metabolic framework for understanding endothelial responses to biologically transformed SiO₂NPs and their potential relevance to nanoparticle-induced vascular dysfunction.