These mechanisms may occur simultan

These mechanisms may occur simultaneous resulting in a quickantibacterial action on the cell.In case of gram-positive S. aureus cells, a large number ofnanoparticles were found on the surface of the cells rather thaninside them as in E. coli. This may be due to the difference in thecomposition of the cell wall. The cell wall of gram-positive bac￾teria has a thick peptidoglycan layer and is more difficult topenetrate inside the cells due to its rigid structure as comparedto the gram-negative bacteria which possess a thinner peptido￾glycan layer [41]. A significant shrinkage and deformation inshape were observed after 10 min of treatment which may affectthe permeability and electron transport of the cell. In Fig. 9c, theAgNPs were penetrated inside the cell membrane and the clus￾tering of nanoparticles was observed. The exact mechanism isnot clear but the nanoparticles could have released Ag+ ionswhich might have disturbed the permeability of the cell [37].This is supported by the attachment of the nanoparticles at thesurface of the cell and also the clustering of nanoparticles. InFig. 9d and e, the particles have completely entered the cellforming even bigger cluster of particles. And complete destruc￾tion of the bacterial cell is seen which may be due to the manypathways as described above.5 ConclusionAgNPs have been synthesized using Cinnamon zeylanicum barkextracts in different polar solvents. The results of this study showa very strong correlation between the aldehyde content, antioxi￾dant activity, and growth of the nanoparticles. It was noticed thatdifferent solvent extracts have significant impact on the antioxi￾dant activity and lead to the formation of nanoparticles withdifferent shapes and sizes. The particles grow in different extractsshowing size variations from 2 to 50 nm. AgNPs demonstratedboth bacteriostatic and bactericidal activity with respect to theirsize and shape. Microscopic analysis of E. coli and S. aureuscells treated with the AgNPs illustrated their interaction withthe cell wall, which facilitated their subsequent entry inside thecells. In conclusion, these nanoparticles could be effectively usedfor the development of infection-resistant material such as anano-coating or impregnation for surgical devices, instruments,and wound healing bandages. The subsequent work related to theimpregnation of these AgNPs in polymer matrix and their appli￾cation will be communicated soon.