<p>Shape-dependent antimicrobial activities of silver nanoparticles</p>

Abstract

Purpose: An important application of silver nanoparticles (Ag NPs) is their use as an antimicrobial and wound dressing material. The aim of this study is to investigate the morphological dependence on the antimicrobial activity and cellular response of Ag NPs. Materials and methods: Ag NPs of various shapes were synthesized in an aqueous solution using a simple method. The morphology of the synthesized Ag NPs was observed via TEM imaging. The antimicrobial activity of the Ag NPs with different morphologies was evaluated against various microorganisms ( Escherichia coli [ E. coli ] , Staphylococcus aureus [ S. aureus ] , Pseudomonas aeruginosa [ P. aeruginosa ]). The antimicrobial activity of the Ag NPs was also examined according to the concentration in terms of the growth rate of E. coli . Results: The TEM images indicated that the Ag NPs with different morphologies (sphere, disk and triangular plate) had been successfully synthesized. The antimicrobial activity obtained from the inhibition zone was in the order of spherical Ag NPs > disk Ag NPs > triangular plate Ag NPs. In contrast, fibroblast cells grew well in all types of Ag NPs when the cell viability was evaluated via an MTT assay. An inductively coupled plasma mass assay showed that the difference in the antimicrobial activities of the Ag NPs was closely associated with the difference in the release rate of the Ag ions due to the difference in the surface area of the Ag NPs. Conclusion: The morphological dependence of the antimicrobial activity of the Ag NPs can be explained by the difference in the Ag ion release depending on the shape. Therefore, it will be possible to control the antimicrobial activity by controlling the shape and size of the Ag NPs.

Interactions of Gold and Silver Nanoparticles with Bacterial Biofilms: Molecular Interactions behind Inhibition and Resistance

“…Apart from size and concentration, the shape of nanoparticles also matters for their antibacterial activity. In separate reports, Penders et al and Cheon et al proved the dependency of antimicrobial activity on the shape of AuNPs and AgNPs respectively [ 75 , 76 ]. Penders et al prepared gold nanospheres (AuNS), gold nanostars (AuNSts) and gold nanoflowers (AuNFs) and checked their activity against S. aureus biofilm.…”

“…The authors speculated that AgNS releases higher amounts of silver ions, which interact with planktonic bacteria and kill them. Thus, as compared to AgNDs and AgNTr, which had lower surface areas and thus lower rates of silver ion release, AgNS had the highest activity [ 76 ]. In all aforementioned reports, the authors also showed a concentration-dependent rise in nanoparticle activity against bacteria [ 73 , 74 , 75 , 76 ].…”

Phytosynthesized Metallic Nanoparticles—between Nanomedicine and Toxicology. A Brief Review of 2019′s Findings

“…For example, the antibacterial effect of nanoparticles has previously been presented to be superior in the case of smaller dimension NPs in studies against different bacterial and fungal lines [126][127][128]. At the same time, spherical nanoparticles have been shown to possess a superior antimicrobial potential compared with cubical, plate-shaped or triangular nanoparticles [126,129].…”

Фототермическое действие инфракрасного (808 nm) лазерного излучения и наночастиц золота в различных модификациях на S. aureus

“…Влияние формы НЧ при антимикробном воздействии определяется механизмом этого действия. В тех случаях, когда контакт клеточной стенки и НЧ влечет за собой необратимые разрушения (действие активных форм кислорода (АФК), повреждения при миграции энергии при плазмонном резонансе), более выраженный эффект достигается наличием развитой поверхности [41][42][43]. При фотодинамической или фототермической терапии с использованием инфракрасного лазерного излучения предпочтительно использовать НЧ с настраиваемым плазмонным резонансом в окне прозрачности тканей при 750−900 nm, и первым выбором в этом случае являются наностержни [44,45].…”