Exploiting Covalent, H-Bonding, and π–π Interactions to Design Antibacterial PDMS Interfaces That Load and Release Salicylic Acid

Sorzabal Bellido, ioritz ORCID: 0000-0001-8050-1443, Diaz Fernandez, YA ORCID: 0000-0003-3422-8663, Skelton, AA, Susarrey Arce, Arturo, McBride, F ORCID: 0000-0003-2985-3173, Prior, IA ORCID: 0000-0002-4055-5161, Beckett, Alison ORCID: 0000-0001-8377-325X and Raval, rasmita (2019) Exploiting Covalent, H-Bonding, and π–π Interactions to Design Antibacterial PDMS Interfaces That Load and Release Salicylic Acid. ACS Appl. Bio Mater., 2 (11). pp. 4801-4811.

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Official URL: http://dx.doi.org/10.1021/acsabm.9b00562

Abstract

Smart antimicrobial surfaces are a powerful tool to prevent bacterial colonization at surfaces. In this work, we report a successful strategy for the functionalization of polydimethylsiloxane (PDMS) surfaces, widely used in medical devices, with salicylic acid (SA), a biocide approved for use in humans. Antimicrobial PDMS surfaces were fabricated via a rational design in which bifunctional silane linker molecules were covalently grafted onto the PDMS via one end, while soft intermolecular interactions with SA were generated at the other end to enable reversible load and release of the biocide. A molecular level understanding of the interface was obtained using attenuated total reflectance Fourier transform infrared, Raman, and X-ray photoelectron spectroscopies, alongside density functional theory calculations. These reveal that the linker molecules dock the SA molecules at the surface via a 1:1 complexation interaction. Furthermore, each 1:1 complex acts as a nucleation point onto which multiple stacks of the biocide are subsequently stabilized via a combination of H-bonding and π-π stacking interactions, thus significantly enhancing SA uptake at the interface. The antimicrobial activity of these surfaces against model Gram-negative and Gram-positive bacteria represented by Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis is demonstrated by a log 6 reduction of planktonic bacterial populations and an efficient anti-biofilm activity at the surface.

Item Type:	Article
Uncontrolled Keywords:	antimicrobial surfaces, functionalized PDMS, salicylic acid, APTES, IPTES, medical device materials
Depositing User:	Symplectic Admin
Date Deposited:	16 Oct 2019 11:04
Last Modified:	19 Jan 2023 00:22
DOI:	10.1021/acsabm.9b00562
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3058370