Influence of poly‐l‐lysine molecular weight on antibacterial efficacy in polymer multilayer films

Abstract

Antibacterial coatings can prevent and treat medical device‐associated infections. We examined the antibacterial properties of coatings assembled from poly‐l‐lysine (PLL) and hyaluronic acid (HA). PLL/HA films were fabricated using layer‐by‐layer assembly with three different PLL MWs, differentiated by number of repeat units, that is, 33, 91, and 407 (denoted by PLL30, PLL90, and PLL400). Films assembled with all three PLL MWs completely inhibited the growth of planktonic, gram‐positive Staphylococcus aureus and methicillin‐resistant S. aureus and gram‐negative Pseudomonas aeruginosa and Escherichia coli over a 24‐h exposure. All three film architectures also inhibited S. aureus attachment by ~60–70% compared to non‐film‐coated surfaces, likely attributed to significant film hydration and electrostatic repulsion due to HA. The true differences in antibacterial efficacy between different PLL MWs were observed upon repeated exposure of PLL/HA to S. aureus every 24 h. We found that PLL400 films lost the ability to inhibit planktonic S. aureus growth after one use while PLL30 and PLL90 films were effective over 4–5 and 9–13 repeated exposures, respectively. Our experiments indicated that differences in efficacy were related to low in‐film mobility of PLL400 and also agreed with dissolution timescales for PLL30 and PLL90 films. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1324–1339, 2019.

Layer-By-Layer Assemblies of Biopolymers: Build-Up, Mechanical Stability and Molecular Dynamics

“…This was first shown by Picart et al (2002) [ 128 ], demonstrating that within HA/PLL PEMs, PLL was able to diffuse throughout the whole PEM to interact with HA at the surface to form polyelectrolyte complexes, contributing to a new layer, and leading to an exponential increase in PEM thickness. Later, it was demonstrated that the distribution of PLL within PEMs depends on its dynamics, which is correlated with the degree of its polymerization ( Figure 5 ) [ 129 ].…”

“…The scale bar is 10 μm. Figure taken from reference [ 129 ], Copyright © 2020 John Wiley and Sons Ltd.…”

Advances in Biomaterials for the Prevention and Disruption of Candida Biofilms

“…As an alternative to solvent casting or vapor deposition approaches, many biomedical surfaces have been coated via layer-by-layer (LbL) self-assembly to develop antifungal coatings. LbL assembly is a multilayer film fabrication method that involves alternating the adsorption of molecules and macromolecules (e.g., polyelectrolytes, peptides, proteins, small molecules, etc.,) with complementary functionalities most commonly by dip coating (Shukla and Almeida, 2014;Alkekhia and Shukla, 2019;Alkekhia et al, 2020). LbL films have been combined with antifungal peptides to exhibit remarkable antibiofilm properties.…”

Polyelectrolyte Multilayer Capsule (PEMC)-Based Scaffolds for Tissue Engineering

“…Thus, this aids in the achievement of the desired scaffold properties such as integral stability, permeability, mechanical properties, etc [ 100 ]. Moreover, the chemical nature and molecular weight of the polymers must also be considered [ 131 ]. There is a high risk for a low-molecular-weight polymer to diffuse into the interior of the porous vaterite CaCO 3 core.…”