Design of Smart Antifouling Surfaces Using Enzyme-Responsive Surface Topographies

Biofilm accumulation on polymeric surfaces remains a persistent challenge in biomedical, industrial, and environmental systems. Here, we report an enzyme-responsive antifouling surface that integrates particle-generated topography with biologically activated surface renewal. Microparticles of poly(ethylene terephthalate) (PET) and the chitinase-responsive polymer PHEVD were generated by mechanical abrasion and embedded into poly(dimethylsiloxane) (PDMS) to create polymer-composite surfaces with three-dimensionally distributed microparticles. PET served as a nonenzyme-responsive control while PHEVD provided an enzyme-degradable phase designed to respond to bacterial activity. Particle-containing PDMS surfaces significantly reduced 24 h Escherichia coli RP437/pRSH109 biofilm biomass, with 2000-grit PHEVD surfaces producing the strongest inhibition and reducing biomass by 86 ± 3% relative to flat PDMS. In contrast, Pseudomonas aeruginosa PAO1 biofilm biomass after 24 h was not significantly reduced by either PET- or PHEVD-containing surfaces, indicating species-dependent early-stage antibiofilm behavior. However, after 7 days, PHEVD-containing surfaces significantly reduced mature PAO1 biofilm biomass. Under static culture, 600- and 2000-grit PHEVD surfaces reduced PAO1 biomass by 60.0 ± 5.5% and 71.0 ± 13.4%, respectively. Under shaking culture at 200 rpm, 600-grit PHEVD reduced retained PAO1 biomass by 93.6 ± 0.03% compared with flat PDMS and by 93.1 ± 0.03% compared with 600-grit PET. These results suggest that PHEVD-containing surfaces do not primarily prevent early PAO1 attachment but instead promote mature biofilm destabilization and removal. The observed 7-day PAO1 reduction is consistent with a coupled mechanism in which mechanical disturbance exposes PHEVD-rich domains, enabling PAO1-associated enzymatic activity to degrade the exposed PHEVD phase and weaken the biofilm-surface interface. This work establishes a facile strategy for designing biologically activated antifouling surfaces that convert microbial enzymatic activity into a trigger for prolonged biofilm control.