Sliver nanoparticles accelerate skin wound healing in mice [Mus musculus] through suppression of innate immune system

This study aimed to find the effects of silver nanoparticles [Ag-NPs] [40 nm] on skin wound healing in mice Mus musculus when innate immune system has been suppressed. A group of 50 BALB/c mice of about 8 weeks [weighting 24.2 +/- 3.0 g] were randomly divided into two groups: Ag-NPs and control group, each with 25 mice. Once a day at the same time, a volume of 50 microliters from the nanosilver solution [10ppm] was applied to the wound bed in the Ag-NPs group while in the untreated [control] group no nanosilver solution was used but the wound area was washed by a physiological solution. The experiment lasted for 14. Transforming growth factor beta [TGF-beta], complement component C3, and two other immune system factors involving in inflammation, namely C-reactive protein [CRP] and rheumatoid factor [RF] in sera of both groups were assessed and then confirmed by complement CH50 level of the blood. The results show that wound healing is a complex process involving coordinated interactions between diverse immunological and biological systems and that Ag-NPs significantly accelerated wound healing and reduce scar appearance through suppression of immune system as indicated by decreasing levels of all inflammatory factors measured in this study. Exposure of mice to Ag-NPs can result in significant changes in innate immune function at the molecular levels. The study improves our understanding of nanoparticle interaction with components of the immune system and suggests that Ag-NPs have strong anti-inflammatory effects on skin wound healing and reduce scarring

Histopathological effects of nanosilver [Ag-NPs] in liver after dermal exposure during wound healing

With the advent of nanotechnology, significant progress has been made in the area of nanoscale materials such as nanosilver [Ag-Nps]. These nanoparticles have a wide range of applications and been used for antimicrobial purposes for more than a century. However, little attention has been paid to the toxicity of nanosilver wound dressing. This study was designed to investigate the possible histopathological toxicity of Ag-NPs in liver of mice during wound healing. A group of 50 female BALB/c mice of about 8 weeks were randomly divided into two groups: Ag-NPs and control groups [n=25]. After creating similar wound on the backs of all animals, the wound bed was treated in Ag-NPs group, with a volume of 50 microliters of the nanosilver solution [10ppm] ,and in control group, with the same amount of distilled water. The experiment lasted for 14 days. Histopathaological samplings of liver were conducted on days 2, 7 and 14 of the experiment. Histopathological studies demonstrated time-dependent changes in mice liver treated with Ag-NPs compared to control group. Some changes include dilation in central venous, hyperemia, cell swelling, increase of Kupffer and inflammatory cells. This study suggests that use of nanosilver for wound healing may cause a mild toxicity, as indicated by time-dependent toxic responses in liver tissue. However, this issue will have to be considered more extensively in further studies

Characterization of an interesting novel mutant strain of commercial Saccharomyces cerevisiae

The yeast strains that are resistant to high concentration of ethanol have biotechnological benefits and are suitable models for physiology and molecular genetics research fields. A novel ethanol-tolerant mutant strain, mut1, derived from the commercial Saccharomyces cerevisiae showed higher ethanol production, and also demonstrated resistance to ethanol but not to other alcohols, such as methanol, 2-propanol, and 1-butanol. To characterize mut1, the strain's resistance to other organic compounds and osmotic and cell wall stresses were examined. The growth of the mut1 strain in the presence of ethyl n-caproate and 3-methyl butyl acetate, which were metabolic derivatives of ethanol, was found to be less than the wild type. On the other hand, the growth of the mut1 strain in the presence of 50% [w/v] sucrose and 1M NaCl was similar to that of the wild type. The sensitivity to cell wall digestive enzyme, zymolyase, was also similar in both wild and mut1 strains. Finally, the mut1 strain showed resistance to homocysteine and serine but was sensitive to methionine. These results suggest that the ethanol resistance of the mut1 strain may be more related to the ethanol metabolic and signalling pathways rather than the enhanced stress resistances relating to the membrane or cell wall compositions

[Application of genetic engineering in changing of saccharomyces cervisiae metabolism]

Saccharomyces cerevisiae is the most important industrial yeast for production of biochemical components, recombinant proteins and single-cell protein. We can use various genetic engineering methods for changing of yeast metabolic pathway[s] to increase of substrate source range such as xylose and lactose, increase of production efficiency and facilitate of industrial fermentation process. These modifications are discussed in new phylome of biology named "metabolic engineering". Here we are going to introduce a brief expression of this scientific field