Antibacterial Properties of Silver Nanoclusters with Carbon Support on Flexible Polymer

Autologous serum protein stabilized silver quantum clusters as host-specific antibacterial agents

Aim: To synthesize host-specific serum protein stabilized silver quantum clusters and assess their preclinical safety as potential antibacterial agents.Materials & methods: Ag-QC-NanoSera (Ag-QCNS) were synthesized using bovine, human and murine sera. Antibacterial efficacy was evaluated against E. coli (including antibiotic-resistant strain), S. aureus and P. aeruginosa. Biocompatibility, hemocompatibility and antibacterial mechanism were also investigated. Preclinical safety and biodistribution of autologous Ag-QCNS were assessed in BALB/c mice over 28 days.Results: Ag-QCNS showed high biocompatibility, hemocompatibility and high antibacterial activity at ∼12.72 μg/ml Ag equivalent. Intracellular ROS and bacterial membrane damage were confirmed as antibacterial mechanism. Ag-QCNS were established as preclinically safe.Conclusion: Ag-QCNS demonstrate potential as next-generation host-specific nanotheranostic antibacterial agents, enhancing the safety and efficacy while combating antibiotic resistance.

In Situ Fabrication of Silver Nanoparticle-Decorated Polymeric Vesicles for Antibacterial Applications

Silver/polymeric vesicle composite nanoparticles with good antibacterial properties were fabricated in this study. Silver nanoparticles (AgNPs) were prepared in situ on cross-linked vesicle membranes through the reduction of silver nitrate (AgNO3) using polyvinylpyrrolidone (PVP) via coordination bonding between the Ag+ ions and the nitrogen atoms on the vesicles. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM) analyses confirmed the formation of AgNPs on the vesicles. The antibacterial test demonstrated good antibacterial activity against both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) for the produced AgNP-decorated vesicles. The minimum inhibitory concentration (MIC) values of the AgNP-decorated vesicles for E. coli and S. aureus were 8.4 and 9.6 μg/mL, respectively. Cell viability analysis on the A549 cells indicated that the toxicity was low when the AgNP concentrations did not exceed the MIC values, and the wound healing test confirmed the good antibacterial properties of the AgNP-decorated vesicles.

Nanostructures on Fluoropolymer Nanotextile Prepared Using a High-Energy Excimer Laser

This study is focused on polytetrafluoroethylene (PTFE) porous nanotextile and its modification with thin, silver sputtered nanolayers, combined with a subsequent modification with an excimer laser. The KrF excimer laser was set to single-shot pulse mode. Subsequently, the physico chemical properties, morphology, surface chemistry, and wettability were determined. Minor effects of the excimer laser on the pristine PTFE substrate were described, but significant changes were observed after the application of the excimer laser to the polytetrafluoroethylene with sputtered silver, where the formation of a silver nanoparticles/PTFE/Ag composite was described, with a wettability similar to that of a superhydrophobic surface. Both scanning electron microscopy and atomic force microscopy revealed the formation of superposed globular structures on the polytetrafluoroethylene lamellar primary structure, which was also confirmed using energy dispersive spectroscopy. The combined changes in the surface morphology, chemistry, and thus wettability induced a significant change in the PTFE's antibacterial properties. Samples coated with silver and further treated with the excimer laser 150 mJ/cm² inhibited 100% of the bacterial strain E. coli. The motivation of this study was to find a material with flexible and elastic properties and a hydrophobic character, with antibacterial properties that could be enhanced with silver nanoparticles, but hydrophobic properties that would be maintained. These properties can be used in different types of applications, mainly in tissue engineering and the medicinal industry, where water-repellent materials may play important roles. This synergy was achieved via the technique we proposed, and even when the Ag nanostructures were prepared, the high hydrophobicity of the system Ag-polytetrafluorethylene was maintained.

Antibacterial Applications of Nanomaterials

In the 21st century, infections remain a major problem for society and are one of the leading causes of mortality [...].

Research Progress on Antibacterial Coatings for Preventing Implant-Related Infection in Fractures: A Literature Review

Implant-related infection is a difficult problem in orthopaedics as it not only leads to failure in internal fixation, but also increases the financial burden and perioperative risk on patients. In the past, orthopaedic implants were designed as mechanical fixation devices simply to maintain mechanical and biological properties, not to regulate the surrounding biological microenvironment. More recently, antimicrobial biocoatings have been incorporated into orthopaedic implants to prevent and treat implant-related infections through the modulation of the local environment. This article reviews the application of orthopaedic-implant biocoating in the prevention of implant-caused infection. Although there are many candidate coatings, they are still in the preclinical testing stage, and thus additional research by biomaterials and clinicians is necessary to identify the ideal implant coatings for patients who require fracture surgery.