Antimicrobial films of poly(2-aminoethyl methacrylate) and its copolymers doped with TiO2 and CaCO3

Authors:

• Kamil Wojciechowski,
• Małgorzata Gutarowicz,
• Jolanta Mierzejewska,
• Paweł Parzuchowski

Abstract

Polymeric coatings with positive surface charge offer potential antimicrobial activity, which they owe to a simple electrostatic attraction with negatively charged bacterial walls and membranes. We describe synthesis and characterization of poly(2-aminoethyl methacrylate) and its copolymers with methyl methacrylate and butyl acrylate, as potential binders for antimicrobial solvent-cast paints. TiO₂ and CaCO₃ mineral particles were employed as model pigments/fillers, as they are used in most real-life paint formulations. Electrokinetic (ζ) potential and antimicrobial activity of thin films made of the (co)polymers in the absence and presence of TiO₂ and CaCO₃ nanopowders were assessed using streaming current measurements and microbial growth inhibition tests, respectively. Independently of the structure of the monomers used for the synthesis, the films showed positive ζ-potential values (up to +95 mV) in the pH range 3.5-8.0. The presence of mineral particles at 50% dry weight of the films did not affect significantly the ζ(pH) curves. The films made of the mixed dispersions remained positively charged and inhibited growth of both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, as well as yeast (C. albicans). The mixed polymeric-mineral films described in this study seem to be promising potential candidates for designing antimicrobial coatings aimed to prevent spreading of bacterial infections.