title: Iron oxide nanoparticles inducePseudomonas aeruginosagrowth, induce biofilm formation, and inhibit antimicrobial peptide function.
abstract: Given the increased use of iron-containing nanoparticles in a number of applications, it is important to understand any effects that iron-containing nanoparticles can have on the environment and human health. Since iron concentrations are extremely low in body fluids, there is potential that iron-containing nanoparticles may influence the ability of bacteria to scavenge iron for growth, affect virulence and inhibit antimicrobial peptide (AMP) function. In this study,Pseudomonas aeruginosa(PA01) and AMPs were exposed to iron oxide nanoparticles, hematite (α-Fe2O3), of different sizes ranging from 2 to 540 nm (2 ± 1, 43 ± 6, 85 ± 25 and 540 ± 90 nm) in diameter. Here we show that the greatest effect on bacterial growth, biofilm formation, and AMP function impairment is found when exposed to the smallest particles. These results are attributed in large part to enhanced dissolution observed for the smallest particles and an increase in the amount of bioavailable iron. Furthermore, AMP function can be additionally impaired by adsorption onto nanoparticle surfaces. In particular, lysozyme readily adsorbs onto the nanoparticle surface which can lead to loss of peptide activity. Thus, this current study shows that co-exposure of nanoparticles and known pathogens can impact host innate immunity. Therefore, it is important that future studies be designed to further understand these types of impacts.
authors.affiliation: Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Borcherding
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Jonas
authors.initials: J
authors.lastname: Baltrusaitis
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Haihan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Larissa
authors.initials: L
authors.lastname: Stebounova
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Chia-Ming
authors.initials: CM
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Gayan
authors.initials: G
authors.lastname: Rubasinghege
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Imali A
authors.initials: IA
authors.lastname: Mudunkotuwa
authors.affiliation: Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Caraballo
authors.affiliation: Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Zabner
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Grassian
authors.affiliation: Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Alejandro P
authors.initials: AP
authors.lastname: Comellas