Effect of Iron Oxide Nanoparticles and Amoxicillin on Bacterial Growth in the Presence of Dissolved Organic Carbon

Inhibition of biofilm, quorum-sensing, and swarming motility in pathogenic bacteria by magnetite, manganese ferrite, and nickel ferrite nanoparticles

Resistance to antibiotics by pathogenic bacteria constitutes a health burden and nanoparticles (NPs) are being developed as alternative and multipurpose antimicrobial substances. Magnetite (Fe3O4 np), manganese ferrite (MnFe2O4 np) and nickel ferrite (NiFe3O4 np) NPs were synthesized and characterized using thermogravimetric analysis, transmission electron microscopy, Fourier transformed infra-red, and X-ray diffraction. The minimal inhibitory concentrations (MIC) ranged from 0.625 to 10 mg/mL against gram-positive (Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212), gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) and candida (Candida albicans ATCC 10239 and Candida tropicalis ATCC 13803) species. The NPs exhibited violacein inhibition against Chromobacterium violaceum CV12472 of 100% at MIC and reduced to 27.2% ± 0.8% for magnetite NPs, 12.7% ± 0.3% for manganese ferrite NPs and 43.1% ± 0.2% for nickel ferrite NPs at MIC/4. Quorum-sensing (QS) inhibition zones against C. violaceum CV026 were 12.5 ±0.6 mm for Fe3O4 np, 09.1 ± 0.5 mm for MnFe3O4 NP and 17.0 ± 1.2 mm for NiFe3O4 np. The NPs inhibited swarming motility against P. aeruginosa PA01 and biofilm against six pathogens and the gram-positive biofilms were more susceptible than the gram-negative ones. The NiFe2O4 np had highest antibiofilm activity against gram-positive and gram-negative bacteria as well as highest QS inhibition while Fe3O4 NP had highest biofilm inhibition against candida species. The synthesized magnetic NPs can be used in developing anti-virulence drugs which reduce pathogenicity of bacteria as well as resistance.

Green synthesis of iron nanoparticles: Sources and multifarious biotechnological applications

Green synthesis of iron nanoparticles is a highly fascinating research area and has gained importance due to reliable, sustainable and ecofriendly protocol for synthesizing nanoparticles, along with the easy availability of plant materials and their pharmacological significance. As an alternate to physical and chemical synthesis, the biological materials, like microorganisms and plants are considered to be less costly and environment-friendly. Iron nanoparticles with diverse morphology and size have been synthesized using biological extracts. Microbial (bacteria, fungi, algae etc.) and plant extracts have been employed in green synthesis of iron nanoparticles due to the presence of various metabolites and biomolecules. Physical and biochemical properties of biologically synthesized iron nanoparticles are superior to that are synthesized using physical and chemical agents. Iron nanoparticles have magnetic property with thermal and electrical conductivity. Iron nanoparticles below a certain size (generally 10-20 nm), can exhibit a unique form of magnetism called superparamagnetism. They are non-toxic and highly dispersible with targeted delivery, which are suitable for efficient drug delivery to the target. Green synthesized iron nanoparticles have been explored for multifarious biotechnological applications. These iron nanoparticles exhibited antimicrobial and anticancerous properties. Iron nanoparticles adversely affect the cell viability, division and metabolic activity. Iron nanoparticles have been used in the purification and immobilization of various enzymes/proteins. Iron nanoparticles have shown potential in bioremediation of various organic and inorganic pollutants. This review describes various biological sources used in the green synthesis of iron nanoparticles and their potential applications in biotechnology, diagnostics and mitigation of environmental pollutants.

Iron Nanoparticles Open Up New Directions for Promoting Healing in Chronic Wounds in the Context of Bacterial Infection

Metal nanoparticles play an outstanding role in the field of wound healing due to their excellent properties, and the significance of iron, one of the most widely used metals globally, cannot be overlooked. The purpose of this review is to determine the importance of iron nanoparticles in wound-healing dressings. Prolonged, poorly healing wounds may induce infections; wound infections are a major cause of chronic wound formation. The primary components of iron nanoparticles are iron oxide nanoparticles, which promote wound healing by being antibacterial, releasing metal ions, and overcoming bacterial resistance. The diameter of iron oxide nanoparticles typically ranges between 1 and 100 nm. Magnetic nanoparticles with a diameter of less than 30 nm are superparamagnetic and are referred to as superparamagnetic iron oxide nanoparticles. This subset of iron oxide nanoparticles can use an external magnetic field for novel functions such as magnetization and functionalization. Iron nanoparticles can serve clinical purposes not only to enhance wound healing through the aforementioned means but also to ameliorate anemia and glucose irregularities, capitalizing on iron's properties. Iron nanoparticles positively impact the healing process of chronic wounds, potentially extending beyond wound management.

Recent Advances of Nanoremediation Technologies for Soil and Groundwater Remediation: A Review

Nanotechnology has been widely used in many fields including in soil and groundwater remediation. Nanoremediation has emerged as an effective, rapid, and efficient technology for soil and groundwater contaminated with petroleum pollutants and heavy metals. This review provides an overview of the application of nanomaterials for environmental cleanup, such as soil and groundwater remediation. Four types of nanomaterials, namely nanoscale zero-valent iron (nZVI), carbon nanotubes (CNTs), and metallic and magnetic nanoparticles (MNPs), are presented and discussed. In addition, the potential environmental risks of the nanomaterial application in soil remediation are highlighted. Moreover, this review provides insight into the combination of nanoremediation with other remediation technologies. The study demonstrates that nZVI had been widely studied for high-efficiency environmental remediation due to its high reactivity and excellent contaminant immobilization capability. CNTs have received more attention for remediation of organic and inorganic contaminants because of their unique adsorption characteristics. Environmental remediations using metal and MNPs are also favorable due to their facile magnetic separation and unique metal-ion adsorption. The modified nZVI showed less toxicity towards soil bacteria than bare nZVI; thus, modifying or coating nZVI could reduce its ecotoxicity. The combination of nanoremediation with other remediation technology is shown to be a valuable soil remediation technique as the synergetic effects may increase the sustainability of the applied process towards green technology for soil remediation.

Do Iron Oxide Nanoparticles Have Significant Antibacterial Properties?

The use of metal oxide nanoparticles is one of the promising ways for overcoming antibiotic resistance in bacteria. Iron oxide nanoparticles (IONPs) have found wide applications in different fields of biomedicine. Several studies have suggested using the antimicrobial potential of IONPs. Iron is one of the key microelements and plays an important role in the function of living systems of different hierarchies. Iron abundance and its physiological functions bring into question the ability of iron compounds at the same concentrations, on the one hand, to inhibit the microbial growth and, on the other hand, to positively affect mammalian cells. At present, multiple studies have been published that show the antimicrobial effect of IONPs against Gram-negative and Gram-positive bacteria and fungi. Several studies have established that IONPs have a low toxicity to eukaryotic cells. It gives hope that IONPs can be considered potential antimicrobial agents of the new generation that combine antimicrobial action and high biocompatibility with the human body. This review is intended to inform readers about the available data on the antimicrobial properties of IONPs, a range of susceptible bacteria, mechanisms of the antibacterial action, dependence of the antibacterial action of IONPs on the method for synthesis, and the biocompatibility of IONPs with eukaryotic cells and tissues.

Do Iron Oxide Nanoparticles Have Significant Antibacterial Properties?

The use of metal oxide nanoparticles is one of the promising ways for overcoming antibiotic resistance in bacteria. Iron oxide nanoparticles (IONPs) have found wide applications in different fields of biomedicine. Several studies have suggested using the antimicrobial potential of IONPs. Iron is one of the key microelements and plays an important role in the function of living systems of different hierarchies. Iron abundance and its physiological functions bring into question the ability of iron compounds at the same concentrations, on the one hand, to inhibit the microbial growth and, on the other hand, to positively affect mammalian cells. At present, multiple studies have been published that show the antimicrobial effect of IONPs against Gram-negative and Gram-positive bacteria and fungi. Several studies have established that IONPs have a low toxicity to eukaryotic cells. It gives hope that IONPs can be considered potential antimicrobial agents of the new generation that combine antimicrobial action and high biocompatibility with the human body. This review is intended to inform readers about the available data on the antimicrobial properties of IONPs, a range of susceptible bacteria, mechanisms of the antibacterial action, dependence of the antibacterial action of IONPs on the method for synthesis, and the biocompatibility of IONPs with eukaryotic cells and tissues.

Nanoantibiotics containing membrane-active human cathelicidin LL-37 or synthetic ceragenins attached to the surface of magnetic nanoparticles as novel and innovative therapeutic tools: current status and potential future applications

Nanotechnology-based therapeutic approaches have attracted attention of scientists, in particular due to the special features of nanomaterials, such as adequate biocompatibility, ability to improve therapeutic efficiency of incorporated drugs and to limit their adverse effects. Among a variety of reported nanomaterials for biomedical applications, metal and metal oxide-based nanoparticles offer unique physicochemical properties allowing their use in combination with conventional antimicrobials and as magnetic field-controlled drug delivery nanocarriers. An ever-growing number of studies demonstrate that by combining magnetic nanoparticles with membrane-active, natural human cathelicidin-derived LL-37 peptide, and its synthetic mimics such as ceragenins, innovative nanoagents might be developed. Between others, they demonstrate high clinical potential as antimicrobial, anti-cancer, immunomodulatory and regenerative agents. Due to continuous research, knowledge on pleiotropic character of natural antibacterial peptides and their mimics is growing, and it is justifying to stay that the therapeutic potential of nanosystems containing membrane active compounds has not been exhausted yet.

Characterization and mechanism of the effects of Mg-Fe layered double hydroxide nanoparticles on a marine bacterium: new insights from genomic and transcriptional analyses

BACKGROUND

Layered double hydroxides (LDHs) have received widespread attention for their potential applications in catalysis, polymer nanocomposites, pharmaceuticals, and sensors. Here, the mechanism underlying the physiological effects of Mg-Fe layered double hydroxide nanoparticles on the marine bacterial species Arthrobacter oxidans KQ11 was investigated.

RESULTS

Increased yields of marine dextranase (Aodex) were obtained by exposing A. oxidans KQ11 to Mg-Fe layered double hydroxide nanoparticles (Mg-Fe-LDH NPs). Furthermore, the potential effects of Mg-Fe-LDH NPs on bacterial growth and Aodex production were preliminarily investigated. A. oxidans KQ11 growth was not affected by exposure to the Mg-Fe-LDH NPs. In contrast, a U-shaped trend of Aodex production was observed after exposure to NPs at a concentration of 10 μg/L-100 mg/L, which was due to competition between Mg-Fe-LDH NP adsorption on Aodex and the promotion of Aodex expression by the NPs. The mechanism underling the effects of Mg-Fe-LDH NPs on A. oxidans KQ11 was investigated using a combination of physiological characterization, genomics, and transcriptomics. Exposure to 100 mg/L of Mg-Fe-LDH NPs led to NP adsorption onto Aodex, increased expression of Aodex, and generation of a new Shine-Dalgarno sequence (GGGAG) and sRNAs that both influenced the expression of Aodex. Moreover, the expressions of transcripts related to ferric iron metabolic functions were significantly influenced by treatment.

CONCLUSIONS

These results provide valuable information for further investigation of the A. oxidans KQ11 response to Mg-Fe-LDH NPs and will aid in achieving improved marine dextranase production, and even improve such activities in other marine microorganisms.