Antibacterial activity of iron oxide, iron nitride, and tobramycin conjugated nanoparticles against Pseudomonas aeruginosa biofilms

Abstract

Background: Novel methods are necessary to reduce morbidity and mortality of patients suffering from infections with Pseudomonas aeruginosa. Being the most common infectious species of the Pseudomonas genus, P. aeruginosa is the primary Gram-negative etiology responsible for nosocomial infections. Due to the ubiquity and high adaptability of this species, an effective universal treatment method for P. aeruginosa infection still eludes investigators, despite the extensive research in this area. Results:We report bacterial inhibition by iron-oxide (nominally magnetite) nanoparticles (NPs) alone, having a mean hydrodynamic diameter of ~ 16 nm, as well as alginate-capped iron-oxide NPs. Alginate capping increased the average hydrodynamic diameter to ~ 230 nm. We also investigated alginate-capped iron-oxide NP-drug conjugates, with a practically unchanged hydrodynamic diameter of ~ 232 nm. Susceptibility and minimum inhibitory concentration (MIC) of the NPs, NP-tobramycin conjugates, and tobramycin alone were determined in the PAO1 bacterial colonies. Investigations into susceptibility using the disk diffusion method were done after 3 days of biofilm growth and after 60 days of growth. MIC of all compounds of interest was determined after 60-days of growth, to ensure thorough establishment of biofilm colonies. Conclusions:Positive inhibition is reported for uncapped and alginate-capped iron-oxide NPs, and the corresponding MICs are presented. We report zero susceptibility to iron-oxide NPs capped with polyethylene glycol, suggesting that the capping agent plays a major role in enabling bactericidal ability in of the nanocomposite. Our findings suggest that the alginate-coated nanocomposites investigated in this study have the potential to overcome the bacterial biofilm barrier. Magnetic field application increases the action, likely via enhanced diffusion of the iron-oxide NPs and NP-drug conjugates through mucin and alginate barriers, which are characteristic of cystic-fibrosis respiratory infections. We demonstrate that iron-oxide NPs coated with alginate, as well as alginate-coated magnetite-tobramycin conjugates inhibit P. aeruginosa growth and biofilm formation in established colonies. We have also determined that susceptibility to tobramycin decreases for longer culture times. However, susceptibility to the iron-oxide NP © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article' s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article'

Iron Oxide Nanoparticles as an Alternative to Antibiotics Additive on Extended Boar Semen

“…The antimicrobial potential of Fe 3 O 4 nanoparticles is preserved until their surface gets fully oxidized to γ -Fe 2 O 3. Armijo et al [ 54 ] findings suggest that Fe 3 O 4 NPs are potential alternatives to silver NPs in several antibacterial applications minimizing the cost and enhancing microbial inactivation and elimination. The results of our research are aligned with these findings, reinforcing the future utilization of the antibacterial activity of Fe 3 O 4 NPs as a new perspective to prevent bacteria in semen.…”

Broad spectrum antibacterial photodynamic and photothermal therapy achieved with indocyanine green loaded SPIONs under near infrared irradiation

“…This approach together with the material choice is very promising for bacterial infections as well, especially for biofilms which are difficult to penetrate through. SPIONs have been used to deliver bactericidal agents previously or to cause dark bactericidal effect which required quite high doses and/or toxic coating materials which may pose serious risks in clinic transition [37][38][39].…”

Anti-biofilm Fe3O4@C18-[1,3,4]thiadiazolo[3,2-a]pyrimidin-4-ium-2-thiolate Derivative Core-shell Nanocoatings

“…In this regard, the hybrid nanosystems based on magnetite nanoparticles (MGNPs) could represent an alternative, considering their accessible and versatile preparation, reduced toxicity as well as antimicrobial properties [ 13 , 14 , 15 , 16 ]. MGNPs were authorized as in vivo drug delivery platform, and as a result, several loaded systems with a good antimicrobial activity were recently reported [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…On the other hand, a variety of biomolecules have been used in order to facilitate the interaction of MGNPs with other antimicrobial species [ 20 ], including fatty acids such as stearic and myristic ones [ 17 , 24 ].…”

“…As a result, this paper focuses on the structural characterization and evaluation of the antibiofilm activity of two bioactive nanosystems based on [1,3,4]thiadiazolo [3,2- a ]pyrimidinium derivatives and Fe 3 O 4 @C 18 core@shell nanoparticles against Staphylococcus aureus , Pseudomonas aeruginosa and Candida albicans strains in order to develop a new strategy for preventing both formation and eradication of microbial biofilms formed on medical devices. This research is based on previous data concerning the antimicrobial activity of MGNPs [ 13 , 14 , 15 , 16 ] and synergy observed with antimicrobials [ 17 , 18 , 19 , 20 , 53 , 54 ], a strategy that could be used in order to develop valuable nanocarriers for a controlled or a targeted release of an active agent. The interaction between the MGNPs and the [1,3,4]thiadiazolo[3,2- a ]-pyrimidinium derivatives was facilitated by octadecanoic acid (C 18 ).…”