Enhancing antibacterial efficacy through propolis-infused electroactive polymers: A novel approach to combat antibiotic resistance

The increasing prevalence of antibiotic-resistant illnesses worldwide calls for the development of novel antibacterial strategies, including the ones based on antibacterials materials. This work reports on the combined antibacterial effects of piezoelectric poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) and propolis, a natural antimicrobial agent, on various material structures (2D films and 3D structures) to increase the surface contact area. It is shown that the addition of propolis has a substantial impact on the surface texture and mechanical properties of the materials. In particular, 3D structures exhibit improved distribution of propolis and enhanced mechanical stability in comparison to 2D films. The antibacterial experiments conducted on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) demonstrate a significant increase in the reduction of bacteria, in particular when larger concentrations of propolis are applied and when mechanical stimulation is used at specified frequencies, taking therefore advantage of the surface charge variation associated to the piezoelectric response. It is particularly significant the antibacterial effect on the resistant S.aureus bacteria, emphasising the huge potential of this novel hybrid material in biomedical applications. Thus, it is demonstrated that piezoelectric polymers in combination with natural antibacterial agents, represents a suitable approach to address microbial resistance, with important applications in areas including wound dressings, implant coatings, and high traffic surfaces, among others.