Overview of antimicrobial polyurethane-based nanocomposite materials and associated signalling pathways

Polyurethanes (PUs) are among the most versatile families of polymers with a broad range of applications in several industrial sectors. Various materials can be used to produce PUs with different properties that are suitable for biological applications. Antimicrobial activity is an essential property of PU materials used in the biomedical field and other consumer products. However, microorganisms can easily be adhered to or colonised on the surface of PU-based devices causing serious health issues in humans. Therefore, it is crucial to increase the antibacterial activities of PU polymers in addition to enhancing their electrical, mechanical and thermal prop-erties. The incorporation of various antibacterial materials, including gold (Au), zinc oxide (ZnO), titanium di -oxide (TiO2), silver nanoparticles (AgNPs), chitosan (CS) and carbon nanotubes (CNTs) in PU matrices is an effective approach to improving the antimicrobial properties of PU as well as increasing its physicochemical properties. In this review, the antimicrobial properties of PU-based nanocomposites and their associated mechanisms are discussed. Moreover, we also expect to provide new insights into signalling pathways associated with the physicochemical properties of PU-based nanocomposites.