Investigating the Production of Antimicrobial Nanoparticles by Chlorella vulgaris and the Link to Its Loss of Viability

Chlorella vulgaris from Al-Ahsa, KSA was proved to be an active silver and gold nanoparticle producer. Nanogold and nanosilver particles were characterized using UV-visible spectroscopy, Fourier-transform infrared spectroscopy, and scanning electronmicroscopy. Both nanoparticles were used in the antimicrobial bioassay. The two nanoparticles showed antibacterial activities, with the silver nanoparticles being the most effective. To investigate the argumentative nature of their biosynthesis (i.e., whether it is a biotic or abiotic process), we isolated total ribonucleic acid RNA as an indicator of vitality. RNA was completely absent in samples taken after one week of incubation with silver nitrate and even after one or two days. However, successful extraction was only achievable in samples taken after incubation for one and four hours with silver nitrate. Most importantly, the gel image showed recognizable shearing of the nucleic acid after 4 h as compared to the control. An assumption can be drawn that the synthesis of nanoparticles may start biotically by the action of enzyme(s) and abiotically by action of reducing entities. Nonetheless, with prolonged incubation, excessive nanoparticle accumulation can be deadly. Hence, their synthesis continues abiotically. From the RNA banding profile, we suggest that nanosilver production starts both biotically and abiotically in the first few hours of incubation and then continues abiotically. Nanosilver particles proved to have more of an antimicrobial impact than nanogold and hence are recommended for different applications as antibacterial agents.

In vitro testing of silver-containing spacer in periprosthetic infection management

Deep infection is a serious complication in endoprosthetic surgery. In correlation to the patient local or systemic compromising factors conservative and surgical proceedings has to be evaluated. Systemic antibiotic therapy is the gold standard in infection management. Implanted silver-coated or silver-containing medical devices have been proven to their antimicrobial effectiveness since the 1990s by several investigators. The outcomes showed that long time implantation could cause damaging of the surrounding tissues, especially of adjacent nerves. The aim of our study was to evaluate the release of silver (I) ions from bone cement mixed with either nanosilver particles (AgNPs), different concentrations of silver sulfate (Ag2SO4) or from pure metallic silver strips. Therefore, we choose two methods: the first, called “static model”, was chosen to evaluate the maximal accumulative concentration of silver (I) ions, with the second, called “dynamic model”, we simulated a continuous reduction of the ions. In an additional test design, the different materials were evaluated for their antimicrobial activity using an agar gel diffusion assay. The outcome showed that neither the addition of 1% (w/w) nanosilver nor 0.1% silver sulfate (w/w) to polymethylmethacrylat bone cement has the ability to release silver (I) ions in a bactericidal/antifungal concentration. However, the results also showed that the addition of 0.5% (w/w) and 1% (w/w) silver sulfate (Ag2SO4) to bone cement is an effective amount of silver for use as a temporary spacer.

Impact of Innovative Films Used for the Production of Silage on Biochemical and Microbial Product Qualities

The production of silage is carried out in cylindrical bales covered with polyethylene foils. In this study, a novel approach was tested towards obtaining an innovative composition of these films. In the first stage of the experiment, different additives, including microcellulose and nanosilver particles, were analyzed. The second stage was aimed at testing the applicability of recycled polyethylene as a film component. The forage value after ensiling was assessed during storage. In order to evaluate the microbial forage quality, the abundance of lactic acid bacteria was determined and compared with the number of aerobic bacteria, yeasts, and molds. The foil properties were also analyzed with the appropriate chemical and microbiological methods. The results showed no significant differences (p < 0.05) between the standard commercial films and tested formulae. In the second stage, obtained results suggested that the film with the addition of nanosilver may be successfully used in agriculture.

Green Synthesis of Silver Nanoparticles Using Pelargonium Quercetorum Agnew and Their Therapeutic Properties

AimThe synthesis of nanosilver particles (AgNPs) from Pelargonium quercetorum Agnew. (Geraniaceae) and evaluation of the antimicrobial and the cytotoxic potential of AgNPs. Materials & MethodsThe synthesized AgNPs were evaluated for antimicrobial and anticancer efficacy using the minimum inhibition concentration method and MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium bromide) assay. ResultsThe AgNPs inhibited approximately 90% the growth of gram-positive Staphylococcus aureus and gram-negative Esherichia coli and yeast Candida albicans pathogens at a concentration of 500 µg/mL. The synthesized AgNPs showed excellent toxicity in MCF-7 cells, and specifically, pq70 AgNP inhibited the growth of MCF-7 cells by 52% at a concentration of 3.125 µg/mL. ConclusionIt was determined that the AgNPs, which had been synthesized from extracts that contained a high phenolic composition, were smaller in size, and showed high anticancer and antimicrobial properties.

New insight into naturally formed nanosilver particles: role of plant root exudates

Manufactured silver nanoparticles (nAg) have been extensively studied because of questions and concerns on their unique properties, behavior and associated impacts on environmental health and safety. In contrast, naturally formed...