Artificial Channels in an Infectious Biofilm Created by Magnetic Nanoparticles Enhanced Bacterial Killing by Antibiotics

Abstract

The poor penetrability of many biofilms contributes to the recalcitrance of infectious biofilms to antimicrobial treatment. Here, a new application for the use of magnetic nanoparticles in nanomedicine to create artificial channels in infectious biofilms to enhance antimicrobial penetration and bacterial killing is proposed. Staphylococcus aureus biofilms are exposed to magnetic‐iron‐oxide nanoparticles (MIONPs), while magnetically forcing MIONP movement through the biofilm. Confocal laser scanning microscopy demonstrates artificial channel digging perpendicular to the substratum surface. Artificial channel digging significantly (4–6‐fold) enhances biofilm penetration and bacterial killing efficacy by gentamicin in two S. aureus strains with and without the ability to produce extracellular polymeric substances. Herewith, this work provides a simple, new, and easy way to enhance the eradication of infectious biofilms using MIONPs combined with clinically applied antibiotic therapies.

Quantitative Photoacoustic Diagnosis and Precise Treatment of Inflammation In Vivo Using Activatable Theranostic Nanoprobe

“…Bacterial infections are a major public heath challenge worldwide, and are estimated to be the primary cause of disease‐related mortality by year 2050. [ 7 ] The emergence of drug resistant strains due to antibiotics overuse has greatly limited the efficacy of currently available drugs. [ 7,8 ] Therefore, novel strategies are needed that can effectively clear bacteria without inducing resistance.…”

“…[ 7 ] The emergence of drug resistant strains due to antibiotics overuse has greatly limited the efficacy of currently available drugs. [ 7,8 ] Therefore, novel strategies are needed that can effectively clear bacteria without inducing resistance. Previous studies have shown that an endogenous biological energy source can generate hydrogen peroxide (H 2 O 2 ) in the inflamed region and kill the infiltrating pathogens.…”

Antimicrobial Metal Nanomaterials: From Passive to Stimuli‐Activated Applications

“…[ 10,12 ] By rupturing the biofilm matrix, the protective layer is removed and planktonic cells are released into the surrounding medium, which are far easier targets for the majority of antimicrobial agents. While there has been limited research into this area, the studies which investigate nanomaterials for magnetophysical antimicrobial activity have utilized vastly different methods, including gold‐iron microrods, [ 277 ] Fe 3 O 4 nanoparticles in combination with additional antimicrobial agents, [ 278–280 ] aggregated Fe 3 O 4 particles, [ 281 ] and gallium alloy‐iron liquid metal droplets. [ 282 ] The mode‐of‐action of these materials varies greatly, as such this review will introduce the concept behind each technology.…”

“…Quan et al used iron oxide nanoparticles (278 ± 61 nm) as a method to magnetically create artificial channels in the biofilm to allow enhanced dissemination of antimicrobial agents within the biofilm ( Figure ,i). [ 278 ] Two strains of S. aureus , differentiated by their ability to produce EPS, were allowed to grow into a mature biofilm, after which they were treated with iron oxide nanoparticles and varying concentrations of gentamicin. Following treatment, there was an observed four to sixfold reduction in viable cells in the presence of gentamicin (1250 µg mL −1 ) and magnetically activated iron oxide nanoparticles, compared to the gentamicin on its own.…”

“…Reproduced with permission. [ 278 ] Copyright 2019, Wiley‐VCH. ii) Enhanced biofilm penetration for microbial control by polyvalent phages conjugated with magnetic colloidal nanoparticle clusters (CNCs).…”