scholarly journals Green synthesized silver nanoparticles destroy multidrug resistant bacteria via reactive oxygen species mediated membrane damage

2017 ◽  
Vol 10 (6) ◽  
pp. 862-876 ◽  
Author(s):  
Balaram Das ◽  
Sandeep Kumar Dash ◽  
Debasish Mandal ◽  
Totan Ghosh ◽  
Sourav Chattopadhyay ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Feng Gao ◽  
Tianyi Shao ◽  
Yunpeng Yu ◽  
Yujie Xiong ◽  
Lihua Yang

AbstractActing by producing reactive oxygen species (ROS) in situ, nanozymes are promising as antimicrobials. ROS’ intrinsic inability to distinguish bacteria from mammalian cells, however, deprives nanozymes of the selectivity necessary for an ideal antimicrobial. Here we report that nanozymes that generate surface-bound ROS selectively kill bacteria over mammalian cells. This result is robust across three distinct nanozymes that universally generate surface-bound ROS, with an oxidase-like silver-palladium bimetallic alloy nanocage, AgPd0.38, being the lead model. The selectivity is attributable to both the surface-bound nature of ROS these nanozymes generate and an unexpected antidote role of endocytosis. Though surface-bound, the ROS on AgPd0.38 efficiently eliminated antibiotic-resistant bacteria and effectively delayed the onset of bacterial resistance emergence. When used as coating additives, AgPd0.38 enabled an inert substrate to inhibit biofilm formation and suppress infection-related immune responses in mouse models. This work opens an avenue toward biocompatible nanozymes and may have implication in our fight against antimicrobial resistance.


2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Emerson Danguy Cavassin ◽  
Luiz Francisco Poli de Figueiredo ◽  
José Pinhata Otoch ◽  
Marcelo Martins Seckler ◽  
Roberto Angelo de Oliveira ◽  
...  

Chemotherapy ◽  
2021 ◽  
Author(s):  
Yassmin Isse Wehelie ◽  
Naveed Ahmed Khan ◽  
Itrat Fatima ◽  
Areeba Anwar ◽  
Kanwal Kanwal ◽  
...  

Background: Acanthamoeba castellanii is a pathogenic free-living amoeba responsible for blinding keratitis and fatal granulomatous amoebic encephalitis. However, treatments are not standardized but can involve the use of amidines, biguanides, and azoles. Objectives: The aim of this study was to synthesize a variety of synthetic tetrazole derivatives and test their activities against A. castellanii. Methods: A series of novel tetrazole compounds were synthesized by one-pot method and characterized by NMR and mass spectroscopy. These compounds were subjected to amoebicidal, and cytotoxicity assays against A. castellanii belonging to the T4 genotype and human keratinocyte skin cells respectively. Additionally, reactive oxygen species determination and electron microscopy studies were carried out. Furthermore, two of the seven compounds were conjugated with silver nanoparticles to study their antiamoebic potential. Results: A series of seven tetrazole derivatives were synthesized successfully. The selected tetrazoles showed anti-amoebic activities at 10µM concentration against A. castellanii in vitro. The compounds tested caused increased reactive oxygen species generation in A castellanii, and significant morphological damage to amoebal membranes. Moreover, conjugation of silver nanoparticles enhanced antiamoebic effects of two tetrazoles. Conclusions: The results showed that azole compounds hold promise in the development of new formulations of anti-Acanthamoebic agents.


Author(s):  
Zi-Yu Chen ◽  
Yu-Chen Su ◽  
Fong-Yu Cheng ◽  
Shian-Jang Yan ◽  
Ying-Jan Wang

Engineered nanoparticles raise safety concerns. Silver nanoparticles (AgNPs) exert acute and chronic adverse effects by inducing reactive oxygen species (ROS)-mediated stress signaling pathways. We investigated the mechanisms by which AgNPs...


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