Salt-Responsive Killing and Release Antibacterial Surfaces of Mixed Polymer Brushes

Stimuli-responsive surfaces with switchable bacterial killing and release are new promising candidates for the development of new antibacterial materials. Although such surfaces have been extensively studied and many advances have been achieved, a number of challenges are remained, including the optimization of structure, moderate stimuli, and so forth. In this paper, we developed a new killing and release antibacterial surface by combining poly[2-(tert-butylamino) ethyl methacrylate] (polyTA) and poly(3-(dimethyl (4-vinylbenzyl) ammonio) propyl sulfonate) (polyDVBAPS) via mixed brushes system. The bactericidal activity of polyTA and salt-responsive property of polyDVBAPS could be well integrated in this way. Accordingly, the surface showed high bactericidal activity by killing more than 94% attached bacteria of E. coli and S. aureus and excellent release capability by detaching most attached bacteria in response to salt solution. Both bacterial killing effectiveness and release rate were well retained at a high level of more than 90% after four severe killing and release cycles, indicating the high reliability of surface regeneration. This excellent antibacterial potency made the surface capable to be used in many biological applications, particularly in reusable devices.