Antimicrobial Activities of Hydrophobically Modified Poly(Acrylate) Films and Their Complexes with Different Chain Length Cationic Surfactants

Ioana Cătălina Gîfu,Ioana Cătălina Gîfu,Ioana Cătălina Gîfu,Monica Elisabeta Maxim,Sabina Georgiana Burlacu,Sabina Georgiana Burlacu,Mihai Anastasescu,Cristina Lavinia Nistor,Cristina Lavinia Nistor,Ludmila Otilia Cinteza,Raluca Ianchis,Raluca Ianchis,Dan-Florin Anghel,Cristian Petcu,Cristian Petcu,Anca Ruxandra Leontieș,Marcela Popa,Claudia Mihaela Ninciuleanu,Claudia Mihaela Ninciuleanu,Ludmila Aricov

doi:10.3390/coatings9040244

Abstract

Multilayer films from hydrophobically modified poly(acrylic acid) (HMPA) and their complexes with cationic surfactants were successfully prepared using the layer-by-layer (LbL) method. Alkyl trimethylammonium bromide derivatives with various lengths of the hydrophobic chain (C10–C18) were used to interact with the HMPA polymer, generating highly hydrophobic domains in the films and contributing to the antimicrobial properties of the prepared coating. The antimicrobial efficiency against common pathogens such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans was investigated in relationship with the morphology and composition of the thin films. The wettability and roughness of the multilayered systems were evaluated using atomic force microscopy (AFM) and contact angle measurements. The effects of the microbial exposure on the surface properties of the prepared films were investigated in order to assess the stability of the HMPA-deposited multilayers and the durability of the antimicrobial activity. The hydrophobically modified films exhibited antimicrobial activity against the studied pathogens. The best efficiency was registered in the case of S. aureus, which showed an inhibition of growth up to 100% after 2 h. C. albicans proved to be less sensitive to the effect of the multilayers deposited from HMPA–surfactant complexes. These results suggest that HMPA and HMPA–surfactant complex LbL multilayer films can be used as promising materials in antimicrobial surface coatings with increased resistance to pathogens during exposure.

Highlights

Polymeric materials are widely used as antimicrobial nanocoatings to prevent biocontamination, which has a direct impact on human health
From the LbL deposition method, thin films consisting of a mixture of hydrophobically modified polymers and surfactants were obtained
C18 were used in order to improve the antimicrobial activity and to modify the morphology of the thin film

Summary

Introduction

Polymeric materials are widely used as antimicrobial nanocoatings to prevent biocontamination, which has a direct impact on human health. The antimicrobial efficiency of a thin film is mainly related to the chemical composition, while the self-cleaning effect is due to its morphology. Both the material and the preparation method influence the biological behavior of polymeric nanostructured films. The layer-by-layer (LbL) self-assembly technique is a useful method to prepare highly hydrophobic and/or antimicrobial multilayer films due to the simplicity of the experimental conditions. It allows extended variation of properties by evaluating molecular interactions between the different types of materials used and tuning the composition [9,10]. It is possible to combine different properties of certain materials to create new synergetic systems, such as superhydrophobic architectures with antibacterial or antifungal properties

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Results

Conclusion