Coating iron oxide nanoparticles with mesoporous silica reduces their interaction and impact on S. oneidensis MR-1. (December 2019)

• Record Type: Journal Article
• Authors: Buchman, Joseph T.; Pho, Thomas; Rodriguez, Rebeca S.; Feng, Z. Vivian; Haynes, Christy L.
• Is Part Of: Chemosphere. Volume 237(2019)
• Publication Date: 2019-12
• Subjects: Nanotoxicity -- Bacteria -- Iron oxide -- Silica -- Dissolution -- Gene expression; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124511
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Here, we investigate the impact of iron oxide nanoparticles (IONPs) and mesoporous silica-coated iron oxide nanoparticles (msIONPs) on Shewanella oneidensis in an aerobic environment, which is likely the main environment where such nanoparticles will end up after use in consumer products or biomedical applications. Monitoring the viability of S. oneidensis, a model environmental organism, after exposure to the nanoparticles reveals that IONPs promote bacterial survival, while msIONPs do not impact survival. These apparent impacts are correlated with association of the nanoparticles with the bacterial membrane, as revealed by TEM and ICP-MS studies, and upregulation of membrane-associated genes. However, similar survival in bacteria was observed when exposed to equivalent concentrations of released ions from each nanomaterial, indicating that aqueous nanoparticle transformations are responsible for the observed changes in bacterial viability. Therefore, this work demonstrates that a simple mesoporous silica coating can control the dissolution of the IONP core by greatly reducing the amount of released iron ions, making msIONPs a more sustainable option to reduce perturbations to the ecosystem upon release of nanoparticles into the environment. Graphical abstract: Image 1 Highlights: Iron oxide nanoparticles enhance survival of the bacterium, Shewanella oneidensis. Dissolved iron released from IONPs recapitulates growth pattern observed with NP exposure. A mesoporous silica coating reduces IONP dissolution, thus mitigating their impact. Changes in gene expression demonstrate a nanoparticle-specific effect.