Synergistic Charge Reversal with Hierarchical Architecture for Self-Adaptive Antibacterial Surface of Polymer Substrate

Abstract

The responsive antibacterial efficacy of hierarchical polymer brushes has been well recognized for the treatment of device-associated infection. However, in the previous work, the nanometer-scale thickness of polymer brushes is prone to damage and the reported silicon substrate is not close to practical application. To address these challenges, a self-adaptive antibacterial polymer surface is facilely proposed and designed. Herein, a two-layered polymer brush is first constructed onto the polymer surface, the inner layer of which is conjugated by dimethylmaleic anhydride (DMMA) to produce charge-reversal function, subsequently loading antimicrobial peptides (AMP), and the outer layer of which is a hydrated brush to provide anti-biomass adhesion function. It's worth noting that the micrometer-scale thickness of the inner layer presents the excellent AMP loading capacity. Compared with the charge-neutralization surface, the charge-reversal surface can more sensitively and controllably release AMP triggered by the acidic environment arising from the metabolism of bacteria and may still be bactericidal after AMP is completely released due to the exposure of the primary amino group, thus the long-term antibacterial of the surface is readily obtained. More importantly, in a mice model the charge-reversal surface demonstrates the highly effective anti-infection and excellent biocompatibility, which implies a promising strategy for the clinical prevention of device-associated infections.