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

PK Forooshani, E Polega, K Thomson, MSA Bhuiyan, R Pinnaratip, M Trought, C Kendrick, Y Gao, KA Perrine, L Pan, BP Lee*
September 24, 2019
Frontiers in Chemistry 7, 631, 2019.
Abstract:

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-1) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg mL-1) 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 formation 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 crosslinking. When PDA-coated mesh was hydrated in phosphate saline buffer (pH 7.4), it was activated to generate 200 ┬ÁM hydrogen peroxide (H2O2) for over 48h. The sustained release of low doses of H2O2 was antibacterial against both gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. PDA coating achieved 100% reduction (LRV ~3.15) when incubated against E. coli and 98.9% reduction (LRV ~1.97) against S. epi in 24h.

 

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