Antibacterial activity of SPIONs versus ferrous and ferric ions under aerobic and anaerobic conditions: a preliminary mechanism study

Abstract

In modern medicine, major attention has been paid to superparamagnetic iron oxide nanoparticles (SPIONs). Recent studies have shown the antibacterial properties of SPIONs against some Gram-positive and Gram-negative bacterial strains. These nanoparticles (NPs) can bind to bacterial membranes via hydrophobic or electrostatic interactions and pass through cell barriers. In this study, the authors evaluated the antibacterial activity of magnetic NPs in comparison with ferrous and ferric ions. The level of reactive oxygen species (ROS) in the treated Staphylococcus aureus and Escherichia coli bacteria were directly measured by fluorometric detection. The results showed that iron ions and SPIONs had significant dependent antimicrobial activities. SPIONs showed greater inhibitory effects than ferrous and ferric ions against the growth of treated bacterial strains under anaerobic conditions, while in aerobic conditions, ferrous showed the strongest antibacterial activity. In anaerobic conditions, they observed the greatest ROS formation and lowest minimum inhibitory concentration in the SPION-treated group in comparison with the other groups. It seems that the release of iron ions from SPIONs and subsequent activation of ROS pathway are the main antibacterial mechanisms of action. Nevertheless, the greater antibacterial effect of SPIONs in anaerobic conditions represents other mechanisms involved in the antibacterial activity of these NPs

Antimicrobial Activity of Isoniazid in Conjugation with Surface-Modified Magnetic Nanoparticles against Mycobacterium tuberculosis and Nonmycobacterial Microorganisms

“…6 Journal of Nanomaterials (7,19). Naked MNPs, usually by adhering to the cell membrane, release reactive oxidative species (ROS) that could initiate a series of oxidation reactions leading to protein and lipid peroxidation (7,10,20). So far, different natural and synthetic structures have been applied to reform MNP surfaces.…”

“…Therefore, the combination of INH with these nontoxic, biocompatible materials (7,8), could alleviate the developing resistance. MNPs also could display antibacterial activity, yet, due to unwanted oxidative effects of iron oxide on cellular structure, it is preferable to modify the particle surface by proper substances (9,10).…”

Exploring the bone sparing effects of postbiotics in the post-menopausal rat model

“…The intervention period was 4 weeks. At the end of the treatment period, rats were sacrificed and used for DEXA analysis [ 21 , 29 ]. One week after rats’ adaption to the animal room, they were allocated to twelve groups (seven rats in each group): (1) Control group: fed with normal saline; (2) OVX group: fed with normal saline; (3) OVX + Lactobacillus acidophilus supernatant: fed with 1 × 10 9 CFU/ml/day of Lactobacillus acidophilus supernatant; (4) OVX + Lactobacillus casei supernatant: fed with 1 × 10 9 CFU/ml/day of Lactobacillus casei supernatant; (5) OVX + Lactobacillus reuteri supernatant: fed with 1 × 10 9 CFU/ml/day of Lactobacillus reuteri supernatant; (6) OVX + Bacillus coagulans supernatant: fed with 1 × 10 9 CFU/ml/day of Bacillus coagulans supernatant; (7) OVX + Bifidobacterium longum supernatant: fed with 1 × 10 9 CFU/ml/day of Bifidobacterium longum supernatant; (8) OVX + Lactobacillus acidophilus lysate: fed with 1 × 10 9 CFU/ml/day of Lactobacillus acidophilus lysate; (9) OVX + Lactobacillus casei lysate: fed with 1 × 10 9 CFU/ml/day of Lactobacillus casei lysate; (10) OVX + Lactobacillus reuteri lysate: fed with 1 × 10 9 CFU/ml/day of Lactobacillus reuteri lysate; (11) OVX + Bacillus coagulans lysate: fed with 1 × 10 9 CFU/ml/day of Bacillus coagulans lysate; (12) OVX + Bifidobacterium longum lysate: fed with 1 × 10 9 CFU/ml/day of Bifidobacterium longum lysate.…”

Bioinorganic Synthesis of Polyrhodanine Stabilized Fe3O4/Graphene Oxide in Microbial Supernatant Media for Anticancer and Antibacterial Applications

“…After separately adding each test microorganism to microplates and after incubation for 24 h, the optical density was read using an ELISA plate reader (BioTek, USA) at 600 nm. MIC was defined when a concentration of compounds (90%) of the bacterial growth was inhibited [ 27 ].…”