Exploring Antibacterial Activity and Bacterial-Mediated Allotropic Transition of Differentially Coated Selenium Nanoparticles

Abstract

The use of metal nanoparticles (NPs) as antimicrobial agents has become a promising alternative to the problem of antibiotic-resistant bacteria and other applications. Silver nanoparticles (AgNPs) are well-known as one of the most universal biocide compounds. However, selenium nanoparticles (SeNPs) recently gained more attention as effective antimicrobial agents. This study aims to investigate the antibacterial activity of SeNPs with different surface coatings (BSA-coated, chitosan-coated, and undefined coating) on the Gram-negative Stenotrophomonas bentonitica and the Gram-positive Lysinibacillus sphaericus in comparison to AgNPs. The tested NPs had similar properties, including shape (spheres), structure (amorphous), and size (50−90 nm), but differed in their surface charge. Chitosan SeNPs exhibited a positive surface charge, while the remaining NPs assayed had a negative surface charge. We have found that cell growth and viability of both bacteria were negatively affected in the presence of the NPs, as indicated by microcalorimetry and flow cytometry. Specifically, undefined coating SeNPs displayed the highest percentage values of dead cells for both bacteria (85−91%). An increase in reactive oxygen species (ROS) production was also detected. Chitosan-coated and undefined SeNPs caused the highest amount of ROS (299.7 and 289% over untreated controls) for S. bentonitica and L. sphaericus, respectively. Based on DNA degradation levels, undefined-SeNPs were found to be the most hazardous, causing nearly 80% DNA degradation. Finally, electron microscopy revealed the ability of the cells to transform the different SeNP types (amorphous) to crystalline SeNPs (trigonal/monoclinical Se), which could have environmentally positive implications for bioremediation purposes and provide a novel green method for the formation of crystalline SeNPs. The results obtained herein demonstrate the promising potential of SeNPs for their use in medicine as antimicrobial agents, and we propose S. bentonitica and L. sphaericus as candidates for new bioremediation strategies and NP synthesis with potential applications in many fields.

Nanotechnology’s frontier in combatting infectious and inflammatory diseases: prevention and treatment

“…The antibacterial mechanism includes four aspects: the delivery of antibiotics, 390 targeting bacterial toxins, damaging bacterial cell walls and membranes, 402 and destroying bacterial DNA, proteins, and enzymes. 417 d Nanotechnology applications against parasites. A variety of NPs targeting the parasite’s growth cycle have been used in the prevention and treatment of malaria: killing Plasmodium larvae in the environment and blocking the transmission pathway; generating antibodies to Plasmodium by nano-vaccination; 438 and destroying Plasmodium in the liver and blood stages.…”

“…Among them, undefined-SeNPs perform best in inducing DNA damage (around 80% of DNA degraded). 417 The multifunctional gold-silver carbon QDs nano-hybrid composite constructed by Ang and colleagues can also increase the ROS content in bacteria and play an antibacterial role under both UV irradiation and non-irradiation conditions. 418 …”

Bioinspired Superhydrophobic Nanocoating Based on Polydopamine and Nanodiamonds to Mitigate Bacterial Attachment to Polyvinyl Chloride Surfaces in Food Industry Environments

“…Several surface modification and coating technologies have been developed to combat bacterial biofilm formation on abiotic surfaces. − Generally, these technologies can be grouped into two categories. , The first group, consisting of antibacterial coatings, contain materials such as peptides, metal nanoparticles, , and charged polymers , that inactivate bacterial cells that come into close proximity of the coated surfaces. Antibacterial efficacy can also be achieved through the strategic design of surface texture and topography. , Specifically, the incorporation of sharp nanofeatures has been reported to inactivate bacteria by inducing mechanical stresses and ruptures in bacterial cell membranes. − Namely, these mechano-bactericidal actions, mediated by precisely engineered sharp nanostructures, provide a physical means of bacterial inactivation .…”