Amphiphilic polymer coated carbon nanotubes: A promising platform against Salmonella typhi

Carbon nanotubes (CNTs) are an excellent example of new nanostructures that can penetrate bacterial cell walls. Its remarkable physical features and potent antibacterial activity make it a promising candidate for various applications. However, two significant barriers currently limit the antibacterial potential of CNTs in medical devices: cell toxicity and CNTs aggregation within a polymer matrix. In this study, a simple and cost-effective method was proposed to synthesize multi-walled carbon nanotubes-g-[poly(ethylene glycol)-bpoly(ε-caprolactone)] (PEG-PCL@CNTs) using biocompatible amphiphilic PEG-PCL diblock copolymer via non-covalent functionalization. Furthermore, time-killing kinetic, ROS generation experiments and SEM analysis demonstrated that PEG-PCL@CNTs exhibited antibacterial activities against S. typhi strains through cell membrane disruption with the release of cellular contents and ROS generation. Excellent hemocompatibility with decreased hemolysis ratios was demonstrated by the PEG-PCL@CNTs nanohybrid materials. Thus, PEG-PCL incorporation may successfully lessen both bacterial adhesion and the toxicity of CNT to human cells. These findings suggest a new avenue for rational design of polymer-functionalization of carbon nanomaterials as therapeutic agents for bacterial infections.