Nanoceria is a multifaceted enzyme-like catalyst of ROS-mediated (reactive oxygen species) reactions, which results in its multiple biomedical applications. Biodegradable polysaccharide coatings improve biocompatibility, while the effects of these coatings on the ROS-related activity of nanoceria in cells need thorough studies. Here, we used human embryonic lung fibroblasts to study the effects of maltodextrin and chitosan coatings on cellular oxidative metabolism of nanoceria by examining cell viability, mitochondrial potential, accumulation of nanoparticles in cells, intracellular ROS, expression of NOX4 (NADPH oxidase 4), NRF2 (nuclear factor erythroid 2-related factor 2), NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), and STAT3 (signal transducer and activator of transcription 3) proteins as well as the expression of biomarkers of DNA damage/repair, cell proliferation, and autophagy. Both types of polysaccharide-coated nanoceria were non-toxic up to millimolar concentrations. For maltodextrin-coated nano-CeO