AUTHOR=Kord Forooshani Pegah , Polega Elizabeth , Thomson Kevin , Bhuiyan Md. Saleh Akram , Pinnaratip Rattapol , Trought Mikhail , Kendrick Chito , Gao Yuesheng , Perrine Kathryn A. , Pan Lei , Lee Bruce P. 

TITLE=Antibacterial Properties of Mussel-Inspired Polydopamine Coatings Prepared by a Simple Two-Step Shaking-Assisted Method

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00631

DOI=10.3389/fchem.2019.00631

ISSN=2296-2646

ABSTRACT=<p>A simple two-step, shaking-assisted polydopamine (PDA) coating technique was used to impart polypropylene (PP) mesh with antimicrobial properties. In this modified method, a relatively large concentration of dopamine (20 mg ml<sup>−1</sup>) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg ml<sup>−1</sup>) to promote the formation and deposition of large aggregates of PDA nanoparticles. Gentle shaking (70 rpm) was employed to increase the deposition of PDA nanoparticle aggregates and the formation of a thicker PDA coating with nano-scaled surface roughness (RMS = 110 nm and Ra = 82 nm). Cyclic voltammetry experiment confirmed that the PDA coating remained redox active, despite extensive oxidative cross-linking. When the PDA-coated mesh was hydrated in phosphate saline buffer (pH 7.4), it was activated to generate 200 μM hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) for over 48 h. The sustained release of low doses of H<sub>2</sub>O<sub>2</sub> was antibacterial against both gram-positive (<italic>Staphylococcus epidermidis</italic>) and gram-negative (<italic>Escherichia coli</italic>) bacteria. PDA coating achieved 100% reduction (LRV ~3.15) when incubated against <italic>E. coli</italic> and 98.9% reduction (LRV ~1.97) against <italic>S. epi</italic> in 24 h.</p>