Controlling the Antimicrobial Action of Surface Modified Magnesium Hydroxide Nanoparticles.

Ahmed F Halbus,Vesselin N Paunov,Tommy S Horozov

doi:10.3390/biomimetics4020041

Ahmed F Halbus, Vesselin N Paunov + Show 1 more

Open Access

https://doi.org/10.3390/biomimetics4020041

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Abstract

Magnesium hydroxide nanoparticles (Mg(OH)2NPs) have recently attracted significant attention due to their wide applications as environmentally friendly antimicrobial nanomaterials, with potentially low toxicity and low fabrication cost. Here, we describe the synthesis and characterisation of a range of surface modified Mg(OH)2NPs, including particle size distribution, crystallite size, zeta potential, isoelectric point, X-ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). We explored the antimicrobial activity of the modified Mg(OH)2NPs on the microalgae (C. reinhardtii), yeast (S. cerevisiae) and Escherichia coli (E. coli). The viability of these cells was evaluated for various concentrations and exposure times with Mg(OH)2NPs. It was discovered that the antimicrobial activity of the uncoated Mg(OH)2NPs on the viability of C. reinhardtii occurred at considerably lower particle concentrations than for S. cerevisiae and E. coli. Our results indicate that the antimicrobial activity of polyelectrolyte-coated Mg(OH)2NPs alternates with their surface charge. The anionic nanoparticles (Mg(OH)2NPs/PSS) have much lower antibacterial activity than the cationic ones (Mg(OH)2NPs/PSS/PAH and uncoated Mg(OH)2NPs). These findings could be explained by the lower adhesion of the Mg(OH)2NPs/PSS to the cell wall, because of electrostatic repulsion and the enhanced particle-cell adhesion due to electrostatic attraction in the case of cationic Mg(OH)2NPs. The results can be potentially applied to control the cytotoxicity and the antimicrobial activity of other inorganic nanoparticles.

Highlights

The increased proliferation of infectious illnesses that are caused by microorganisms found in food packaging, medical devices, water treatment systems, and domestic appliances has elicited increased interest [1,2,3]
The mean hydrodynamic diameter and zeta potential of the Mg(OH)2 NPs in deionized water were measured by the dynamic light scattering instrument (DLS) of suspensions that were prepared by dispersing 0.025 g of Mg(OH)2 NPs sample in 100 mL of deionized water by a digital sonicator
The major weight loss step has been found in the temperature range of 300–450 ◦ C, which is due to the transition phase, corresponding to the decomposition of Mg(OH)2 NPs to MgO

Summary

Introduction

The increased proliferation of infectious illnesses that are caused by microorganisms found in food packaging, medical devices, water treatment systems, and domestic appliances has elicited increased interest [1,2,3]. The increased resistance of microorganisms against current biocides has caused great concern, for individuals of compromised immune systems [4,5]. This has prompted expanded efforts to investigate new types of nanomaterials as antibacterial agents [6,7,8], which do not rely on the existing pathways of antimicrobial resistance. Mg(OH) NPs have attracted significant attention over the years due to their wide applications in different fields as an environmentally friendly material with low cost of production [14,15,16,17] and they may be potentially used in pharmaceutical formulations [18,19,20,21]

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