Engineering Ulvan-Functionalized Surfaces for Tunable Antimicrobial and Antiadhesive Performance

Ulvan, a sulfated marine polysaccharide, holds promise for antiadhesive and antimicrobial surface coatings. We engineered two ulvan-based coating series by covalently grafting ulvan onto poly(allylamine)-modified substrates using EDC/s-NHS or BDDE cross-linking chemistries. Surface analyses confirmed tunable morphology and composition with coating thickness and ulvan density saturated at defined cross-linker thresholds. Adhesion assays with <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> revealed significantly reduced colonization on all ulvan coatings versus uncoated controls. <i>E. coli</i> adhesion decreased exponentially with ulvan density with nanogel-like coatings also inducing membrane damage. <i>S. aureus</i> exhibited weaker transient responses, possibly due to structural resistance. Correlating biological activity with surface chemistry established ulvan content as a key predictor of performance. These coatings offer short-term protection against microbial colonization, particularly effective during the critical early adhesion phase, and provide a chemically tunable platform for anti-infective surfaces in applications such as catheters, wound dressings, and food-contact materials. This work lays the groundwork for designing glycosylated interfaces in biomedical and environmental applications where early stage biofilm prevention is critical.