Dual-Responsive Supramolecular Antimicrobial Coating Based on Host-Guest Recognition

The adhesion and proliferation of the bacteria on biomedical surfaces have posed a great threat to patients. Developing a class of renewable bactericidal surface with excellent bacteria release capability is crucial for elongating the service life of the biomedical devices. However, releasing the bacteria fast and frequently is usually a trade-off with releasing them thoroughly and completely regenerating the surface. Herein, a temperature/light dual-responsive antimicrobial coating is developed. The cyclodextrin (CD)-contained antifouling macromolecule and the thermal-responsive azobenzene-contained macromolecule are assembled on the CDs-modified surface, combined with additional silver nanoparticles. The surface exhibits low bacteria attachments of 9.30 × 10 5 cells cm −2 ( E. coli , 120 h), high bactericidal efficiency of ≈96.3%. Meanwhile, ≈86.9% of the attached bacteria can be released from the surface rapidly in response to temperature, and the residues can be thoroughly removed by irradiating UV irradiation (release ratio ≈91.0%). The functions of the surface can be resumed by switching the host-guest network via light regulation. The 3 rd regenerated surface still maintains low bacteria density of 12.4 × 10 5 cells cm −2 , bacteria killing ratio of ≈95.0%, and bacteria release rate of ≈95.7%. The work is supposed to provide a new insight into the design of multifunctional antibacterial surface and broaden their applications.