Surface modification of polyurethane biomaterials by ammonia plasma: bacterial adhesion and cellular response - research data

In this study, polyurethane biomaterials were modified using low-temperature ammonia plasma to improve their surface properties for biomedical applications. The treatment introduced amine groups, enhanced surface hydrophilicity, and altered surface polarity without affecting topography. Surface characterization was performed using X-ray photoelectron spectroscopy (XPS), water contact angle measurements, and atomic force microscopy (AFM). The impact of surface modification on bacterial adhesion was assessed using reference strains Pseudomonas aeruginosa DSM 22644, Staphylococcus epidermidis DSM 28319, Staphylococcus aureus DSM 4910, and Escherichia coli DSM 18039. While E. coli adhesion remained unchanged, significantly increased adhesion was observed for P. aeruginosa and S. epidermidis on modified surfaces. At the same time, biocompatibility analysis using A549 cells showed enhanced cell adhesion, spreading, and cytoskeletal organization, confirmed by increased Focal Adhesion Kinase (FAK) expression. The findings demonstrate that ammonia plasma treatment improves cellular compatibility but may promote adhesion of certain bacterial strains, underlining the need to balance antimicrobial resistance and biocompatibility when designing polyurethane-based biomedical materials.