Development and characterization of antibacterial coatings on surgical sutures based on sodium carboxymethyl cellulose/chitosan/chlorhexidine.

The layer-by-layer assembly (LBL) method was used in this work to apply antibacterial coatings to the surface of sutures. The nanofilm was created using sodium carboxymethyl cellulose, chitosan, and chlorhexidine digluconate. Polyethylene terephthalate and polyamide surgical sutures were used as the substrate. At pH 5, thin, uniform coatings with the ideal number of biopolymers in the film (10 bilayers) are produced. The pH and the shape of the polyelectrolyte macromolecules determine the film's thickness and form. The morphology of the surface and the structure of the sutures after modification become homogeneous and smooth. Both treated and untreated sutures retain their mechanical strength, and there is no significant loss of tensile strength. Nanofilms obtained on the surface of the sutures showed high antimicrobial efficacy against microorganisms Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Staphylococcus epidermidis, and Streptococcus pneumoniae. Chlorhexidine incorporated into the multilayer membrane was found to have greater antimicrobial activity than sutures treated with chlorhexidine alone. Modified surgical sutures provide antibacterial qualities that last for up to 30 days in a stable, controlled manner. The results showed the prospects of applying nanofilms based on sodium carboxymethyl cellulose/chitosan/chlorhexidine to surgical sutures that can prevent the infectious consequences of surgical interventions.

Synthesis, characterization of silver/kaolinite nanocomposite and studying its antibacterial activity.

In the present study, silver/kaolinite nanocomposites were synthesized by impregnation in a silver nitrate solution. Silver nanoparticles are deposited onto the surface of the kaolinite by a simple wet reduction of a silver precursor using hydrogen peroxide as a reducing agent. Elemental, mineral composition, structure and morphology of natural kaolinite and synthesized nanocomposites are characterized by X-ray diffractometry, FT-IR spectroscopy, photoluminescence (PL), zeta potential, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The antibacterial activity of AgNPs/kaolinite nanocomposites to Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumoniae, Escherichia coli strains was studied by the minimum inhibitory concentration method. The obtained AgNPs/kaolinite nanocomposite was shown to have antimicrobial potential.

Synthesis and Antibacterial Activity of (AgCl, Ag)NPs/Diatomite Hybrid Composite.

. In the present research, hybrid (AgCl, Ag)NPs/diatomite composites were synthesized by direct impregnation with aqueous silver nitrate solutions. The silver chloride nanoparticles (AgCl-NPs) were formed as an effect of the exchange reaction when silver interacted with the diatomite mineral impurity halite. Nanoparticles of metallic silver (AgNPs) were created by the reduction of silver ions under the influence of hydrogen peroxide. The content of silver chloride nanoparticles in the (AgCl, Ag)NPs/diatomite composite was limited by the content of the halite in the used diatomite. Samples of natural diatomite and synthesized (AgCl, Ag)NPs/diatomite composites were examined by using scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis. Moreover, the antibacterial potential of synthesized composites was also studied using the MIC (minimal inhibitory concentration) method against the most common drug-resistant microorganisms in the medical field: Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumoniae. The obtained hybrid (AgCl, AgNPs)/diatomite composites were shown to have antimicrobial potential. However, widespread use requires further study by using various microorganisms and additional cytotoxic studies on eukaryotic systems, e.g., cell lines and animal models.