Catechol-Functional Chitosan/Silver Nanoparticle Composite as a Highly Effective Antibacterial Agent with Species-Specific Mechanisms.
Sci Rep
; 7(1): 1860, 2017 05 12.
Article
en En
| MEDLINE
| ID: mdl-28500325
ABSTRACT
In this study, silver nanoparticles (Ag NPs) coated with catechol-conjugated chitosan (CSS) were prepared using green methods. Interestingly, we uncovered that CSS-coated Ag NPs (CSS-Ag NPs) exhibited a higher toxicity against gram-negative Escherichia coli (E. coli) bacteria than against gram-positive Staphylococcus aureus (S. aureus) bacteria. The differences revealed that the CSS-Ag NPs killed gram bacteria with distinct, species-specific mechanisms. The aim of this study is to further investigate these underlying mechanisms through a series of analyses. The ultrastructure and morphology of the bacteria before and after treatment with CSS-Ag NPs were observed. The results demonstrated the CSS-Ag NPs killed gram-positive bacteria through a disorganization of the cell wall and leakage of cytoplasmic content. In contrast, the primary mechanism of action on gram-negative bacteria was a change in membrane permeability, induced by adsorption of CSS-Ag NPs. The species-specific mechanisms are caused by structural differences in the cell walls of gram bacteria. Gram-positive bacteria are protected from CSS-Ag NPs by a thicker cell wall, while gram-negatives are more easily killed due to an interaction between a special outer membrane and the nanoparticles. Our study offers an in-depth understanding of the antibacterial behaviors of CSS-Ag NPs and provides insights into ultimately optimizing the design of Ag NPs for treatment of bacterial infections.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Plata
/
Catecoles
/
Quitosano
/
Nanopartículas
/
Antibacterianos
Idioma:
En
Revista:
Sci Rep
Año:
2017
Tipo del documento:
Article
País de afiliación:
China