Self-Sterilizing, Self-Cleaning Mixed Polymeric Multifunctional Antimicrobial Surfaces

Abstract

Mitigation of bacterial adhesion and subsequent biofilm formation is quickly becoming a strategy for the prevention of hospital-acquired infections. We demonstrate a basic strategy for surface modification that combines the ability to control attachment by microbes with the ability to inactivate microbes. The surface consists of two active materials: poly(p-phenylene ethynylene)-based polymers, which can inactivate a wide range of microbes and pathogens, and poly(N-isopropylacrylamide)-based polymers, which can switch between an hydrophobic "capture" state and a hydrophilic "release" state. The combination of these materials creates a surface that can both bind microbes in a switchable way and kill surface-bound microbes efficiently. Considerable earlier work with cationic poly(p-phenylene ethynylene) polyelectrolytes has demonstrated and characterized their antimicrobial properties, including the ability to efficiently destroy or deactivate Gram-negative and Gram-positive bacteria, fungi, and viruses. Similarly, much work has shown (1) that surface-polymerized films of poly(N-isopropylacrylamide) are able to switch their surface thermodynamic properties from a swollen, relatively hydrophilic state at low temperature to a condensed, relatively hydrophobic state at higher temperature, and (2) that this switch can control the binding and/or release of microbes to poly(N-isopropylacrylamide) surfaces. The active surfaces described herein were fabricated by first creating a film of biocidal poly(p-phenylene ethynylene) using layer-by-layer methods, and then conferring switchable adhesion by growing poly(N-isopropylacrylamide) through the poly(p-phenylene ethynylene) layer, using surface-attached polymerization initiators. The resulting multifunctional, complex films were then characterized both physically and functionally. We demonstrate that such films kill and subsequently induce widespread release of Gram-negative and Gram-positive bacteria.

Responsive and Synergistic Antibacterial Coatings: Fighting against Bacteria in a Smart and Effective Way

“…Following this strategy, a series of smart antibacterial coatings were developed by integration of bactericidal components with temperature‐responsive polymers (such as PNIPAAm or poly( N ‐vinylcaprolactam) (PVCL)). In most cases, the two functional components were introduced to the surface in form of either copolymer brushes or mixed polymer brushes and thus multistep reactions are needed. In contrast, a AgNP/PNIPAAm hybrid film prepared using a one‐step photopolymerization method showed a more facial and reliable approach to design a film with smart antibacterial activity .…”

Versatile Antibacterial Materials: An Emerging Arsenal for Combatting Bacterial Pathogens

“…In this scenario, the bacterial‐killing components include quaternary ammonium groups, poly( p ‐phenylene ethynylene), poly[2‐(methacryloyloxy)‐ethyl]trimethylammonium chloride, poly( N,N ‐dimethylaminoethyl methacrylate), antibacterial peptides, lysozyme, etc. The bacterial‐repelling components include polyethylene glycol (PEG), zwitterionic polymers, poly( N ‐isopropylacrylamide) (PNIPAAm), etc.…”

Self-sterilizing ormosils surfaces based on photo-synzthesized silver nanoparticles

“…polymer coatings that control the release of antimicrobial agents (antibiotics, silver ions or nanoparticles), and/or mixed polymers with self-cleaning and self-sterilization properties 9 ; c) inorganic coatings with intrinsic antimicrobial activity such as titanium dioxide, a well-known photosensitizer upon UV light irradiation that provides a high rate of bacterial inactivation 10 .…”

“…It should be noted that the high bactericidal effect of silver loaded ormosil films was reached even in the case of POrs-Ag which does not contain CS particles and presented a slightly lower formation of AgNPs.Although P. aeruginosa showed an exceptional ability to colonize non-loaded metal ormosil substrates, the incorporation of AgNPs into the film decreased dramatically its viability attaining self-sterilization. Much effort has been devoted to the development of biomaterials with effective antimicrobial properties for medical devices in order to prevent biofilms-related infection.Recently Pappas et al9 developed an innovative mixed polymeric surface to inactivate bacterial pathogens. Even though this polymeric material shows promising application as an antimicrobial surface, it was not able to reach the total killing of the attached bacteria (20-30% of the initial inoculum remained viable).…”