While used extensively in the clinic, 1 in 25 patients will experience a healthcareassociated infection, with 65% of these infections linked to biofilm formation. [1] For example, urinary tract infections caused by patient catheterization account for at least 30% of nosocomial infections. [2] To combat this issue, new coatings have been developed, which are either passively resistant to biofilm formation, actively antimicrobial with contact-killing properties, or impregnated with antibiotics or other antimicrobial components, leading to their release. [3-7] A major drawback of several antimicrobial contact-killing polymer coatings, such as quaternary amine-containing polymer coatings and those employing antimicrobial peptides, is that they suffer from poor antifouling properties, resulting in protein adhesion and the accumulation of nonviable matter on the device surface. [3,7] This debris coating then provides a conditioning layer for microorganisms to adhere and form a mature biofilm, thus masking the antimicrobial activity. Conversely, neutral hydrophilic polymers, such as poly(ethylene glycol) and zwitterionic polymers, [5,8,9,10] as well as topological patterns, such as shark-skin mimics and others, [11,12] have been utilized as low-fouling surfaces, yet they typically contain no active antimicrobial component to eradicate Contact-killing antimicrobial coatings are important for reducing medical device related nosocomial bacterial infections, yet they inadvertently suffer from rapid bacterial colonization. To lessen the extent of biofilm formation on such surfaces, it is hypothesized that coatings containing alternating regions of a low-fouling polymer incorporated into a contact-killing surface would reduce bacterial colonization, while still allowing for the contact-killing properties to be retained. To this end, photopatterned surfaces are developed with alternating regions comprised of a crosslinked low-fouling zwitterionic copolymer and regions containing the antimicrobial peptide nisin for contactkilling. The surfaces are characterized by X-ray photoelectron spectroscopy and water contact angle measurements and assessed for their efficacy against Staphylococcus epidermidis colonization. The dual antimicrobial action surfaces present the synergistic advantages of both classes of coatings against the prolific biofilm-forming bacterium, reducing the biofilm surface coverage by 70% relative to the nonpatterned control, while still retaining their contact-killing activity. The results suggest that patterned surfaces, which combine nonadhesive regions with contact killing regions, have the potential to provide improved control over bacterial colonization, biofilm formation, and medical device-associated infections.
