In Vitro Assessment of the Antibacterial Potential of Silver Nano-Coatings on Cotton Gauzes for Prevention of Wound Infections

Abstract

Multidrug-resistant organisms are increasingly implicated in acute and chronic wound infections, thus compromising the chance of therapeutic options. The resistance to conventional antibiotics demonstrated by some bacterial strains has encouraged new approaches for the prevention of infections in wounds and burns, among them the use of silver compounds and nanocrystalline silver. Recently, silver wound dressings have become widely accepted in wound healing centers and are commercially available. In this work, novel antibacterial wound dressings have been developed through a silver deposition technology based on the photochemical synthesis of silver nanoparticles. The devices obtained are completely natural and the silver coatings are characterized by an excellent adhesion without the use of any binder. The silver-treated cotton gauzes were characterized through scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA) in order to verify the distribution and the dimension of the silver particles on the cotton fibers. The effectiveness of the silver-treated gauzes in reducing the bacterial growth and biofilm proliferation has been demonstrated through agar diffusion tests, bacterial enumeration test, biofilm quantification tests, fluorescence and SEM microscopy. Moreover, potential cytotoxicity of the silver coating was evaluated through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide colorimetric assay (MTT) and the extract method on fibroblasts and keratinocytes. Inductively coupled plasma mass spectrometry (ICP-MS) was performed in order to determine the silver release in different media and to relate the results to the biological characterization. All the results obtained were compared with plain gauzes as a negative control, as well as gauzes treated with a higher silver percentage as a positive control.

Antimicrobial Silver Nanoparticles for Wound Healing Application: Progress and Future Trends

“…In their study, Thuptimdang et al analyzed the effect of silver nanoparticles on Pseudomonas putida biofilms at different levels of maturity and showed a higher effect of AgNPs on less mature biofilms [86]. Paladini et al demonstrated the efficacy of silver nanocoatings deposited on textile materials for wound dressing in preventing bacterial adhesion and biofilm formation [87,88,89]. Figure 2 reports the scanning electron microscopy images of S. aureus colonies adhered and proliferated on flax fibers and different stages of bacterial proliferation and biofilm formation, from single bacterial cells (Figure 2a) to a dense and thick layer of bacteria (Figure 2c).…”

Antimicrobial activity of tellurium‐loaded polymeric fiber meshes

“…Comparing these results to those obtained with fibers loaded with silver nanoparticles (≈4 log reduction in bacterial numbers), Te‐loaded fibers show a lower log reduction . However, it is important to remember the numerous detrimental side effects avoided by bypassing the use of silver nanoparticles in toxic concentrations.…”

Bioinspired Materials for Wound Healing Application: The Potential of Silk Fibroin

“…Along with the well-known antimicrobial properties [ 117 , 118 , 119 , 120 ], some studies have also demonstrated a role of silver nanoparticles in wound healing, which can further improve the biological properties of fibroin through the development of fibroblasts into myofibroblasts, thus promoting wound contraction and healing rate, and stimulating keratinocyte proliferation [ 121 , 122 , 123 , 124 ].…”