Interaction of green silver nanoparticles with model membranes: possible role in the antibacterial activity.

PABLO R. DALMASSO; ANIKE P.V. FERREYRA MAILLARD; AXEL HOLLMANN; BEATRIZ A. LÓPEZ DE MISHIMA; PABLO R. DALMASSO; ANIKE P.V. FERREYRA MAILLARD; AXEL HOLLMANN; BEATRIZ A. LÓPEZ DE MISHIMA

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 171 p. 320 - 326

0927-7765

Silver nanoparticles (AgNPs) constitute a very promising approach for overcoming the emergence of antibioticresistance bacteria. Although their mode of action could be related with membrane damage, the AgNPs-lipidmembrane interaction is still unclear. In this sense, the present work investigated the interaction of model lipidmembranes with AgNPs coated with different capping agents such as citrate (C-AgNPs) and phytomolecules (GAgNPs)obtained via a green synthesis. The AgNPs-membrane interactions were evaluated studying i) the surfacepressure changes on both zwitterionic (DMPC) and negatively charged (DMPC:DMPG) lipid monolayers, ii) thezeta potential and DLS of DMPC:DMPG liposomes and iii) Zeta potential on Escherichia coli membranes, incubatedwith this nanomaterials. The results showed that both negatively charged-AgNPs can interact with theselipid monolayers inducing an increase in the surface pressure but G-AgNPs presented a significantly higheraffinity toward both monolayers in comparison with C-AgNPs. Zeta potential data confirmed again the interactionevent showing that both DMPC:DMPG liposomes and E. coli bacteria became more negative with the addition of G-AgNPs. This increased net negative charge of the liposomes and E. coli allows to indicate aninterfacial interaction where the green nanometal should keep adsorbed to the membrane via the insertion ofaromatic/hydrophobic moieties of capping agents on the surface of AgNPs into the lipid bilayer. Summarizing,the AgNPs-membrane interaction should be an essential step in the antibacterial activity either because themembrane is the main target or by increasing the local concentration of silver from G-AgNPs accumulationwhich could cause the bactericidal effect.