Microfibrillated Cellulose-silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical, Mechanical and Antibacterial Properties

Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a PVA hydrogel modified with cellulose/silver nanocomposites having potential applications in various fields including biomedical, antimicrobial inhibition, textile wears, etc. Microfibrillated cellulose/silver nanocomposites hydrogels were prepared in the aqueous medium with aid of microwave-assisted heating. Different percentages of nanocomposites were incorporated in PVA hydrogel to enhance the properties of PVA hydrogel. Prepared products were characterized by UV-Visible spectroscopy, FTIR, TGA, XRD, and SEM. The swelling (in water saline, acidic and alkaline solution), tensile, thermal, and antibacterial properties were also examined. The formation of Ag nanoparticles (AgNPs) in the (MFC-Ag) NC was confirmed by XRD and UV–Vis spectra. UV–Vis spectra showed the characteristic peaks of Ag in the UV–Vis spectra at 425 nm. Final products exhibited significant porosity and maximum swelling of 519.44%. The thermal stability of hydrogel increased with an increased percentage of (MFC-Ag)NC. Hydrogels exhibited significant antimicrobial inhibition against multidrug-resistant microorganisms, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

Bifunctional manganese oxide–silver nanocomposites anchored on graphitic mesoporous carbon to promote oxygen reduction and inhibit cathodic biofilm growth for long-term operation of microbial fuel cells fed with sewage

Manganese oxide–silver nanocomposites anchored on graphitic mesoporous carbon were synthesized for enhancing oxygen reduction and inhibiting cathodic biofilm growth for the long-term operation of microbial fuel cells.

Hyaluronic Acid-Silver Nanocomposites and Their Biomedical Applications: A Review

For the last years scientific community has witnessed a rapid development of novel types of biomaterials, which properties made them applicable in numerous fields of medicine. Although nanosilver, well-known for its antimicrobial, anti-angiogenic, anti-inflammatory and anticancer activities, as well as hyaluronic acid, a natural polysaccharide playing a vital role in the modulation of tissue repair, signal transduction, angiogenesis, cell motility and cancer metastasis, are both thoroughly described in the literature, their complexes are still a novel topic. In this review we introduce the most recent research about the synthesis, properties, and potential applications of HA-nanosilver composites. We also make an attempt to explain the variety of mechanisms involved in their action. Finally, we present biocompatible and biodegradable complexes with bactericidal activity and low cytotoxicity, which properties suggest their suitability for the prophylaxis and therapy of chronic wounds, as well as analgetic therapies, anticancer strategies and the detection of chemical substances and malignant cells. Cited studies reveal that the usage of hyaluronic acid-silver nanocomposites appears to be efficient and safe in clinical practice.

Comparative Assessment of Silver Nanocomposites’ Biological Effects on the Natural and Synthetic Matrix

The aim of our investigation was to make a comparative assessment of the biological effects of silver nanoparticles encapsulated in a natural and synthetic polymer matrix. We carried out a comparative assessment of the biological effect of silver nanocomposites on natural (arabinogalactan) and synthetic (poly-1-vinyl-1,2,4-triazole) matrices. We used 144 three-month-old white outbred male rats, which were divided into six groups. Substances were administered orally for 9 days at a dose 500 μg/kg. Twelve rats from each group were withdrawn from the experiment immediately after nine days of exposure (early period), and the remaining 12 rats were withdrawn from the experiment 6 months after the end of the nine-day exposure (long-term period). We investigated the parietal–temporal area of the cerebral cortex using histological (morphological assessments of nervous tissue), electron microscopic (calculation of mitochondrial areas and assessment of the quality of the cell nucleus), and immunohistochemical methods (study of the expression of proteins regulating apoptosis bcl-2 and caspase 3). We found that the effect of the nanocomposite on the arabinogalactan matrix causes a disturbance in the nervous tissue structure, an increase in the area of mitochondria, a disturbance of the structure of nerve cells, and activation of the process of apoptosis.