We have developed a novel simple method for effective preparing gold nanoparticles (AuNPs) intended for utilization in biomedicine. The method is based on gold sputtering into liquid poly(ethylene glycol) (PEG). The PEG was used as a basic biocompatible stabilizer of the AuNP colloid. In addition, two naturally occurring polysaccharides - Chitosan (Ch) and Methylcellulose (MC) - were separately diluted into the PEG base with the aims to enhance the yield of the sputtering without changing the sputtering parameters, and to further improve the stability and the biocompatibility of the colloid. The colloids were sterilized by steam, and their stability was measured before and after the sterilization process by dynamic light scattering and UV-Vis spectrophotometry. The results indicated a higher sputtering yield in the colloids containing the polysaccharides. The colloids were also characterized by atomic absorption spectroscopy (AAS) to reveal the composition of the prepared nanoparticles by transmission electron microscopy (TEM) to visualize the nanoparticles and to evaluate their size and clustering, and by rheometry to estimate the viscosity of the colloids. The zeta-potential of the AuNPs was also determined as an important parameter indicating the stability and the biocompatibility of the colloid. In addition, in vitro tests of antimicrobial activity and cytotoxicity were carried out to estimate the biological activity and the biocompatibility of the colloids. Antimicrobial tests were performed by a drip test on two bacterial strains - Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli. AuNP with chitosan proved to possess the highest antibacterial activity, especially towards the Gram-positive S. epidermidis. In vitro tests on eukaryotic cells, i.e. human osteoblastic cell line SAOS-2 and primary normal human dermal fibroblasts (NHDF), were performed after a 7-day cultivation to determine the effect and the toxic dose of the colloids on human cells. The studied colloid concentrations were in the range from 0.6 μg/ml to 6 μg/ml. Toxicity of the colloids started to reappear at a concentration of 4.5 μg/ml, especially with chitosan in the colloid, where the colloid with a concentration of 6 μg/ml proved to be the most toxic, especially towards the SAOS-2 cell line. However, the PEG and PEG-MC containing colloids proved to be relatively non-toxic, even at the highest concentration, but with a slowly decreasing tendency of the cell metabolic activity.

• MeSH
• Anti-Bacterial Agents chemistry   pharmacology   MeSH
• Cell Line MeSH
• Chitosan chemistry   MeSH
• Dynamic Light Scattering MeSH
• Escherichia coli drug effects   MeSH
• Colloids chemistry   MeSH
• Metal Nanoparticles chemistry   MeSH
• Humans MeSH
• Methylcellulose chemistry   MeSH
• Polysaccharides chemistry   MeSH
• Drug Stability MeSH
• Staphylococcus epidermidis drug effects   MeSH
• Sterilization MeSH
• Particle Size MeSH
• Gold chemistry   pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

In this research, influence of storage conditions on properties of oxidized cellulose was studied with respect to its haemostatic function. The aim was to examine changes of the properties of oxidized cellulose stored properly and that stored at laboratory conditions for 2 years. We studied surface morphology and chemical composition, as well as absorption of the simulated body fluid, behaviour in aqueous environment via potentiometric measurement of pH, and antimicrobial activity in vitro on the S. epidermidis bacteria. It was found out that the material properties of oxidized cellulose did not deteriorate. Higher absorption of simulated body fluid, lower pH in water and simulated body fluid represented positive changes with respect to the haemostatic function. Due to the acidic nature of the mate-rial, degraded oxidized cellulose preserved its antibacterial properties.

• MeSH
• Anti-Bacterial Agents analysis   MeSH
• Cellulose, Oxidized * analysis   MeSH
• Microscopy, Electron methods   MeSH
• Photoelectron Spectroscopy methods   MeSH
• Hemostatics analysis   MeSH
• Quality Control MeSH
• Drug Storage MeSH
• Environmental Exposure prevention & control   MeSH
• Publication type
• Clinical Study MeSH
• Research Support, Non-U.S. Gov't MeSH