A photo-triggered coating of prosthetic valve leaflet surface to realize antibacterial and thrombolysis on-demand

Thrombosis formation and bacterial infection pose significant challenges in the clinical application of long-term implanted prosthetic heart valves (PHV), and the two challenges generally occurred in the middle and late stages of implantation. So, it would be very valuable for PHV to realize antibacterial and thrombolysis "on-demand". In this study, we constructed a photo-triggered coating to simultaneously address the above both challenges based on photodynamic therapy (PDT), which has been widely researched due to its advantage of spatiotemporal control. The photosensitizer chlorin e6 (Ce6) were grafted onto the polyethyleneimine (PEI) and introduced into the coating by layer-by-layer (LBL) technology. Under near-infrared (660 nm) irradiation, the coating could release reactive oxygen species (ROS), effectively destroy bacterial walls and disintegrating the fibrin threedimensional network structure of formed thrombi. Therefore, the coating exhibited dual functionality of antibacterial and thrombolysis "on-demand". Experimental results demonstrated that the coating effectively eradicated gram-positive and gram-negative bacteria both in vitro and in vivo, as well as causing thrombolysis under irradiation. These results highlight the potential of this coating in improving the anticoagulation and antibacterial properties of prosthetic heart valves and other long-term implanted devices.