Does improving the biocompatibility of polyurethanes affect bacterial adhesion?
Kamil Drożdż*, Monika Gołda-Cępa**, Monika Brzychczy-Włoch*.
*Department of Molecular Medical Microbiology, Department of Microbiology, Faculty of Medicine, Jagiellonian University Medical College.
**Surface and Materials Chemistry Group, Department of Chemistry, Jagiellonian University in Krakow.
Biocompatibility is one of the main parameters determining the functionality of a biomaterial for medical applications. Currently, there are many products made of polyurethanes on the market, as they are characterized by their flexibility and wear resistance. These materials have found applications in vascular catheters or tracheostomy tubes, among others. In order to increase the biocompatibility of polyurethanes and reduce microbial contamination, new methods of functionalizing these surfaces are being sought.
The aim of this study was to determine the effect of modifying the surface of polyurethanes with low-temperature oxygen plasma on the evaluation of biocompatibility with eukaryotic cells and bacterial adhesion.
Surface modification of polyurethanes was carried out by oxygen plasma using the Diener electronic Femto plasma system. The functionalized surface was characterized by XPS spectroscopy (SES R4000, Gammadata Scienta) and the hydrophilicity of the surface was evaluated by measuring the wetting angle with the Surftens Universal (OEG) instrument. Biocompatibility and cytotoxicity of the cell line (A549) were assessed using FDA and PI stains by fluorescence microscopy. The adherence of the tested strains (E. coli, P. aeruginosa, S. aureus and S. epidermidis) was determined by the percentage of polyurethane surface occupancy by fluorescence microscopy using SYTO9 and PI and by serial dilution method. For this purpose, biomaterials were incubated with 0.5 McF bacterial suspension in PBS for 30, 60 and 240 minutes. The samples were also imaged in a scanning electron microscope (Hitachi S-4700).
Based on the results, it was concluded that the applied modification on the surface of the polyurethanes improved the biocompatibility of the A549 line. An increase in the adhesion of the tested bacterial species to the modified surface was also observed, which is an undesirable effect. Work on new biomaterial surfaces should be a compromise between finding optimal conditions for eukaryotic cells, while not affecting or even reducing the increase in bacterial adhesion to biomaterial surfaces.
Funding source: N41/DBS/000454, directed by Prof. Monika Brzychczy-Włoch, Ph.D.; SONATA 18 (2019/35/D/ST5/03107, directed by Monika Golda-Cępa, Ph.