Cytotoxicity in the Age of Nano: The Role of Fourth Period Transition Metal Oxide Nanoparticle Physicochemical Properties


A clear understanding of physicochemical factors governing nanoparticle toxicity is still in its infancy. We used a systematic approach to delineate physicochemical properties of nanoparticles that govern cytotoxicity. the cytotoxicity of fourth period metal oxide nanoparticles (NPs): TiO2, Cr2O3, Mn2O3, Fe2O 3, NiO, CuO, and ZnO increases with the atomic number of the transition metal oxide. This trend was not cell-type specific, as observed in non-transformed human lung cells (BEAS-2B) and human bronchoalveolar carcinoma-derived cells (A549). Addition of NPs to the cell culture medium did not significantly alter pH. Physiochemical properties were assessed to discover the determinants of cytotoxicity: (1) point-of-zero charge (PZC) (i.e., isoelectric point) described the surface charge of NPs in cytosolic and lysosomal compartments; (2) relative number of available binding sites on the NP surface quantified by X-ray photoelectron spectroscopy was used to estimate the probability of biomolecular interactions on the particle surface; (3) band-gap energy measurements to predict electron abstraction from NPs which might lead to oxidative stress and subsequent cell death; and (4) ion dissolution. Our results indicate that cytotoxicity is a function of particle surface charge, the relative number of available surface binding sites, and metal ion dissolution from NPs. These findings provide a physicochemical basis for both risk assessment and the design of safer nanomaterials.



Second Department

Biological Sciences

Keywords and Phrases

chromium oxide nanoparticle; copper oxide nanoparticle; iron oxide nanoparticle; manganese oxide nanoparticle; metal oxide; nanoparticle; nickel oxide nanoparticle; titanium oxide nanoparticle; unclassified drug; zinc oxide nanoparticle; apoptosis; article; binding site; carcinoma cell; cell compartmentalization; cell viability; controlled study; cytotoxicity; human; human cell; isoelectric point; molecular interaction; nanoanalysis; nanotoxicology; oxidative stress; particle size; physical chemistry; prediction; quantitative analysis; surface property; X ray photoelectron spectroscopy; Cytotoxicity; Metal ion dissolution; Metal oxide nanoparticles; Physicochemical properties; Point-of-zero charge; Surface binding sites; Apoptosis; Binding Sites; Cell Line, Tumor; Cell Survival; Humans; Hydrogen-Ion Concentration; Metal Nanoparticles; Oxides; Surface Properties; Transition Elements; Cytotoxicity; Metal ion dissolution; Metal oxide nanoparticles; Physicochemical properties; Point-of-zero charge; Surface binding sites

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Article - Journal

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© 2013 Elsevier, All rights reserved.

Publication Date

01 Nov 2013