| Nanoscience and Nanotechnology is often considered the fastest growing sector of the high tech economy, and is expected to turn into a trillion US dollar industry by 2015. This new technology offers new opportunities for the use of nanoparticles in both industry and health sectors. Because of their novel properties, engineered nanoparticles may have enhanced toxicity compared to their respective bulk material. Due to growing concerns about the safety of nanoparticles, it is essential to better investigate their effect on a living cell. Currently there is little information on the potential toxicity of metal oxide nanoparticles on human health. Here, we investigate the genetic profile of yeast non-essential gene deletion array (yGDA,- 4700 strains) for increased sensitivity to zinc oxide and silver nanoparticles. Such profiles can be used to better understand the mode of activity of the different nanoparticles. Differential inhibitory effect of different nanoparticles for different gene deletion mutants can provide important clues into the mechanism of toxicity of these compounds. We observed that zinc oxide exhibit its activity against Saccharomyces cerevisiae, mainly by affecting the cytoplasmic membrane and cell wall formation/function. This was apparent from enrichments in membrane function and cell wall deficiencies among the mutant strains with increased sensitivity to zinc oxide nanoparticles. To confirm this observation we performed two secondary assays, cell wall and membrane integrity assays in both the presence and absence of zinc oxide nanoparticles. Also, a chemical genetic profile of silver nanoparticles using yGDA reveals that cellular roles of most susceptible mutants to silver nanoparticles may involve in vesicular transport, cellular respiration, and DNA repair, mainly nucleotide excision repair pathways. This was apparent from analysing the pathway of most susceptible mutant strains with increased sensitivity to silver nanoparticles. |
