Photo-switchable supramolecular comb-like polymer brush based on host-guest recognition for use as antimicrobial smart surface

Bacterial infections from biomedical devices pose a great threat to the health of humans and thus place a heavy burden on society. Therefore, developing efficient antibacterial surfaces has attracted much attention. However, it is a challenge to identify or develop a combination that efficiently integrates multiple functions via topological tailoring and on-demand function-switch via non-contact and noninvasive stimuli. To resolve this issue, a highly hydrophilic comb polymer brush was constructed here based on supramolecular host-guest recognition. Azobenzene (azo)-modified antifouling and antibacterial polymers were incorporated into cyclodextrin (CD)-modified antifouling polymer brushes grafted on the surface. The surface thus obtained possessed excellent antifouling performance with a low bacterial density of similar to 6.25 x 10(5) cells per cm(2) after 48 h and exhibited a high efficiency of similar to 88.2% for killing bacteria. Besides, irradiation with UV light resulted in the desorption of the azo-polymers and a release of similar to 85.1% attached bacteria. Irradiating visible light led to the re-adsorption of azo-polymers, which regenerated the fresh surface; the process could be repeated for at least three cycles, and the surface still maintained low bacterial attachments with a cell density of similar to 7.10 x 10(5) cells per cm(2), high sterilization efficiency of similar to 93.8%, and a bacteria release rate of similar to 83.1% in the 3rd cycle. The photo-switchable antibacterial surface presented in this research will provide new insights into the development of smart biomedical surfaces.