Biofilm Inhibition and Elimination Regulated by Cationic Conjugated Polymers

Abstract

In this work, we demonstrate that water-soluble conjugated polymers (PFP) have the ability to inhibit biofilm formation and eradicate mature established biofilm using reactive oxygen species (ROS) produced by PFP under white light irradiation. Upon addition of PFP to planktonic Staphylococcus aureus (S. aureus), electrostatic interactions bring cationic PFP to the surface of S. aureus, which possesses negative charges. As the amount of PFP coated on S. aureus becomes saturated, the interactions of bacteria to bacteria and bacteria to surface may be disrupted, resulting in reduced biofilm formation. After the biofilm matures, those PFP on the surface of the biofilm can generate ROS under white light irradiation, which has the ability to inactivate bacteria nearby. Once the biofilm is broken, PFP can penetrate throughthe biofilm and continuously generate ROS under irradiation, resulting in biofilm disruption. As a consequence, this makes conjugated polymers a very promising material for the disruption of biofilm in biomedical and industrial applications.

Lactobacillus plantarum lipoteichoic acid inhibits biofilm formation of Streptococcus mutans

“…aureus by electrostatic interaction and turn ζ-potential of S . aureus , which inhibits the bacterial binding to other bacteria or to surface, resulting in inhibited biofilm formation [ 51 ]. Some cationic peptides can penetrate cells to bind to DNA and regulate biofilm-related gene expression in P .…”

Self-Assembled Antimicrobial Nanomaterials

“…Other interesting BSA based on cationic polymers were represented by the light-activated nanomaterials containing conjugated polyelectrolytes adsorbed onto colloidal particles or forming capsules [ 112 , 113 , 145 ]. Some water-soluble conjugated polymers such as poly-{[(9,9-bis(6’- N , N , N -trimethylammonium)hexyl) fluorenylene phenylene]dibromide} (PFP) with positively charged quaternary ammonium (QA) showed biocidal activity due to insertion of QA into the cell membrane and the ability to generate ROS by sensitizing oxygen molecules around, which not only inhibited biofilm formation but also eliminated mature and established biofilms thanks to the reactive oxygen species (ROS) produced by PFP under white light irradiation [ 146 ]. For these quaternary ammonium PFP the total antimicrobial activity reflected the combined light toxicity and dark toxicity.…”

“…For these quaternary ammonium PFP the total antimicrobial activity reflected the combined light toxicity and dark toxicity. Figure 8 reproduced from [ 146 ] illustrates the process of PFP attack against S. aureus biofilms. PFP can penetrate the bacteria biofilm and continuously generate ROS under irradiation, resulting in biofilm disruption.…”

Radical Cation Initiated Surface Polymerization on Photothermal Rubber for Smart Antifouling Coatings

“…Biofouling, caused by nonspecific adhesion and accumulation of microorganism on surfaces, has been a serious problem in the biomedical community and marine industry worldwide for several decades. Increasing the dosage and developing new kinds of bactericides would definitely fight against biofouling by preventing the formation of viable biofilm, but inevitably would have side effects on the environment . Therefore, biofouling‐resistant surfaces possessing minimally fouling‐adhesive properties have been always pursued .…”