Nanosilver–Silica Composite: Prolonged Antibacterial Effects and Bacterial Interaction Mechanisms for Wound Dressings

Abstract

Infected superficial wounds were traditionally controlled by topical antibiotics until the emergence of antibiotic-resistant bacteria. Silver (Ag) is a kernel for alternative antibacterial agents to fight this resistance quandary. The present study demonstrates a method for immobilizing small-sized (~5 nm) silver nanoparticles on silica matrix to form a nanosilver–silica (Ag–SiO2) composite and shows the prolonged antibacterial effects of the composite in vitro. The composite exhibited a rapid initial Ag release after 24 h and a slower leaching after 48 and 72 h and was effective against both methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). Ultraviolet (UV)-irradiation was superior to filter-sterilization in retaining the antibacterial effects of the composite, through the higher remaining Ag concentration. A gauze, impregnated with the Ag–SiO2 composite, showed higher antibacterial effects against MRSA and E. coli than a commercial Ag-containing dressing, indicating a potential for the management and infection control of superficial wounds. Transmission and scanning transmission electron microscope analyses of the composite-treated MRSA revealed an interaction of the released silver ions with the bacterial cytoplasmic constituents, causing ultimately the loss of bacterial membranes. The present results indicate that the Ag–SiO2 composite, with prolonged antibacterial effects, is a promising candidate for wound dressing applications.

Coating of Polyetheretherketone Films with Silver Nanoparticles by a Simple Chemical Reduction Method and Their Antibacterial Activity

“…et al and Ur Rehman M.A. et al [16,64] described a similar effect to the one reported in this study, where the antibacterial properties increased with the increase of the silver nanoparticle ratio and the humid environment in which the samples were installed, such studies demonstrated the effectiveness of the AgNPs coatings in solid state as an antibacterial system. For the antimicrobial test, an uncoated PEEK film was used as a control in the six plates, which did not present antimicrobial activity.…”

The effects of calcium–silicate–hydrate (C–S–H) seeds on reference microorganisms

“…There are many factors affecting the potentially hazardous effects of nanomaterials arising from their size, shape, chemical composition, the tendency to agglomerate, solubility, surface area and charge (Nawrotek and Augustyniak 2015;Miller et al 2017;Augustyniak et al 2019). While the toxicity of nanoparticles has been proven by many studies in laboratory conditions (Aruguete et al 2013;Mosselhy et al 2017;Díez-Pascual 2018), their toxicity under the mass production of cementitious composites may vary due to the fact that most of the nanosized admixtures are not stabilized in a working aqueous suspension. In addition, the full dispersion of nanoparticles in aqueous solution is also hindered due to the limited amount of water that is used for the composite production (Sikora et al 2018).…”

Correction: Granbohm, H, et al. Control of the Size of Silver Nanoparticles and Release of Silver in Heat Treated SiO2-Ag Composite Powders. Materials 2018, 11, 80

“…In the published article “Control of the Size of Silver Nanoparticles and Release of Silver in Heat Treated SiO 2 -Ag Composite Powders” [ 1 ] a reference was omitted in the caption of Figure 4b. A citation to [ 2 ] (Reference [12] in the reference list of [ 1 ]) has been added. This does not change the numbering of the reference list in [ 1 ].…”