Efficacy of silk fibroin&ndash;nano silver against <em>Staphylococcus aureus</em> biofilms in a rabbit model of sinusitis

Abstract

Background Staphylococcus aureus biofilms contribute significantly to the recalcitrant nature of chronic rhinosinusitis. In previous studies, it has been shown that silk fibroin–nano silver solution can eliminate S. aureus biofilms in vitro, which suggests a potential role of this novel agent in the treatment of biofilm-associated diseases, such as sinusitis. Objective The aim of this study was to investigate the efficacy of silk fibroin–nano silver solution as a topical anti-biofilm agent in a rabbit model of sinusitis. Methods Biofilm-associated sinusitis models were established in 24 New Zealand White rabbits by gelatin sponge placement and S. aureus inoculation through a hole drilled into the anterolateral wall of the right maxillary sinus. After 4 weeks, indwelling catheters were placed into the maxillary sinus. Different concentrations of silk fibroin–nano silver solution or normal saline were irrigated slowly into the maxillary sinus via the indwelling catheters. After 7 days of irrigation, the rabbits were sacrificed. The sinus mucosa was harvested and examined for biofilm biomass as well as morphological integrity of the epithelium by scanning electron microscopy. Results Silk fibroin–nano silver solution was found to be most effective in reducing the biomass of the S. aureus biofilms at a concentration of 384 mg/L, followed by the concentration of 153.6 mg/L, when compared with saline. After treatment with 384 mg/L silk fibroin–nano silver solution, the biofilms were completely eliminated and the injured epithelium was almost restored with regenerated cilia on the surface. Conclusion Silk fibroin–nano silver solution was found to be an effective topical agent against S. aureus biofilms in the rabbit model of sinusitis, and its effect was concentration-dependent.

Gentamicin-loaded silk/nanosilver composite scaffolds for MRSA-induced chronic osteomyelitis

“…Tyrosine residues endow SF with the capacity as stabilizers and reduction agents for the biosynthesis of AgNPs. Various strategies have been developed to prepare AgNPs-loaded SF scaffolds for the treatment of skin infections, refractory wounds and sinusitis [10,11]. However, no attempt was reported to use the scaffolds in chronic osteomyelitis.…”

Kaempferol Inhibits the Primary Attachment Phase of Biofilm Formation in Staphylococcus aureus

“…Three principle strategies target the different stages of biofilm development: attachment inhibition, biofilm architecture disruption and signal transduction interference (Chung and Toh, 2014 ). Various inhibitors such as plant-derived natural compounds or synthesized small molecules (Brackman and Coenye, 2015 ; Mogosanu et al, 2015 ), enzymes targeting the matrix (Itoh et al, 2005 ), an enzyme from an S. aureus bacteriophage that degrades the cell wall (Kelly et al, 2012 ), nanoparticles and silver ions (Jia et al, 2017 ), polysaccharides and synthetic peptides with anti-biofilm activity (Rendueles et al, 2013 ; Pletzer and Hancock, 2016 ) have been discovered.…”

Silk Polymers and Nanoparticles: A Powerful Combination for the Design of Versatile Biomaterials

“…Silver NPs are used for antibacterial applications and silk materials have been functionalized with silver NPs. UV irradiation was used to synthetize silver NPs directly in silk solutions (Jia et al, 2017 ), films (Zhou et al, 2019 ), sponges (Hu et al, 2020 ), fibers, textiles and electrospun mats (Calamak et al, 2015 ; Jia et al, 2017 ; Ribeiro et al, 2017 ; Zhou et al, 2019 ; Hu et al, 2020 ; Raho et al, 2020 ). In situ synthesis of NPs in silk textiles was not uniform over the fibers, likely due to a different silver ion adsorption depending on the silk chemical groups.…”