Rapid Assembly of Infection-Resistant Coatings: Screening and Identification of Antimicrobial Peptides Works in Cooperation with an Antifouling Background

Abstract

Bacterial adhesion and the succeeding biofilm formation onto surfaces are responsible for implant-and deviceassociated infections. Bifunctional coatings integrating both nonfouling components and antimicrobial peptides (AMPs) are a promising approach to develop potent antibiofilm coatings. However, the current approaches and chemistry for such coatings are time-consuming and dependent on substrates and involve a multistep process. Also, the information is limited on the influence of the coating structure or its components on the antibiofilm activity of such AMP-based coatings. Here, we report a new strategy to rapidly assemble a stable, potent, and substrate-independent AMP-based antibiofilm coating in a nonfouling background. The coating structure allowed for the screening of AMPs in a relevant nonfouling background to identify optimal peptide combinations that work in cooperation to generate potent antibiofilm activity. The structure of the coating was changed by altering the organization of the hydrophilic polymer chains within the coatings. The coatings were thoroughly characterized using various surface analytical techniques and correlated with the efficiency to prevent biofilm formation against diverse bacteria. The coating method that allowed the conjugation of AMPs without altering the steric protection ability of hydrophilic polymer structure results in a bifunctional surface coating with excellent antibiofilm activity. In contrast, the conjugation of AMPs directly to the hydrophilic polymer chains resulted in a surface with poor antibiofilm activity and increased adhesion of bacteria. Using this coating approach, we further established a new screening method and identified a set of potent surface-tethered AMPs with high activity. The success of this new peptide screening and coating method is demonstrated using a clinically relevant mouse infection model to prevent catheterassociated urinary tract infection (CAUTI).

Bioinspired Polydopamine Coatings Facilitate Attachment of Antimicrobial Peptidomimetics with Broad-Spectrum Antibacterial Activity

“…When dopamine was added to the buffer solution, there was a sharp increase in the percentage of C and N on the surface ( Table 1 ). This can be attributed to a polydopamine layer forming on the material surface [ 41 , 42 ]. When the antibiotic ciprofloxacin was added to the dopamine solution, there was no detection of F on the surface, suggesting that ciprofloxacin was not covalently attached to the surface, and any loosely bound or absorbed compound was removed in the washing process ( Table 1 ).…”

Antimicrobial peptide-based materials: opportunities and challenges

“…The AMPcoated PU catheter significantly reduced the planktonic bacterial population by three logs and bacterial adhesion by four logs in a mouse urinary catheter infection model, thanks to the combined activity of polymer brush and AMP. 281,282 The in vivo imaging system (IVIS) measurement showed a significant reduction in the bacterial population after placing implants in the urinary bladder of mice (Fig. 12B and C).…”

Host Defense Peptide-Mimicking Polymers and Polymeric-Brush-Tethered Host Defense Peptides: Recent Developments, Limitations, and Potential Success

“…While tethered HDPs on polymer brushes minimize the issue to some extent, they do not prevent accumulation. One strategy to overcome this is to use layers with self-cleaning properties or combine antifouling and antimicrobial properties into the polymer brush strategy to repel bacteria and those killed by the surface-exposed HDPs [219,220]. However, we must be concerned whether the antifouling properties of the coated surfaces come at the expense of reducing antimicrobial activity.…”