Salt-Induced Regenerative Surface for Bacteria Killing and Release.

Antibacterial surfaces with both bacteria killing and release functions show great promise in biological and biomedical applications, in particular for reusable medical devices. However, these surfaces either require a sophisticated technique to create delicate structures or need rigorous stimuli to trigger the functions, greatly limiting their practical application. In this study, we made a step forward by developing a simple system based on a salt-responsive polyzwitterionic brush. Specifically, the salt-responsive brush of poly(3-(dimethyl (4-vinylbenzyl) ammonium) propyl sulfonate) (polyDVBAPS) was endowed with bactericidal function by grafting an effective bactericide, i.e., triclosan (TCS). This simple functionalization successfully integrated the bacteria attach/release function of polyDVBAPS and bactericidal function of TCS. As a result, the surface could kill more than 95% attached bacteria and, subsequently, could rapidly detach ∼97% bacteria after gently shaking in 1.0 M NaCl for 10 min. More importantly, such high killing efficiency and release rate could be well retained (unchanged effectiveness of both killing and release after four severe killing/release cycles), indicating the highly efficient regeneration and long-term reusability of this system. This study not only contributes zwitterionic polymers by conferring new functions but also provides a new, highly efficient and reliable surface for "killing-release" antibacterial strategy.