PEGylated-peptide coatings for the preparation of infection-resistant orthopedic implant surfaces

Despite sterilization and aseptic procedures, bacterial infection remains a major impediment to the utility of medical implants including catheters, artificial prosthetics, and subcutaneous sensors. It has been estimated that upwards of 60% of nosocomial infections are associated with implants, with an estimated one million cases per year in the United States alone. In the orthopedic area, infections are the second most commonly attributed cause of implant failure, with the rate of infection associated with external fixators (e.g., pins) estimated to be as high as 85%. However, despite decades of prophylactic antibiotic use, high infection rates continue to persist, particularly with the emergence of drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). Clearly, there is a pressing clinical need for new coatings and treatments to address the issues of implant infection and antimicrobial resistance, preferably using strategies that can be simply and robustly administered to implants.;Herein, we report the development and characterization of a novel PEGylated-peptide surface coating for titanium (Ti), a standard orthopedic implant material. This coating consists of a hydrophilic PEG chain conjugated to a Ti-binding peptide (TBP) anchor. The TBP domain, selected from phage display, spontaneously assembles via adsorptive mechanisms onto Ti, with PEG extending into aqueous solution to afford a non-fouing adlayer resistant to protein adhesion and S. aureus colonization. Using a number of surface analytical techniques, we have further characterized the peptides and the resultant coatings on Ti to identify potential design variations for improved performance and to contribute to the design and engineering of future bacteriophobic coatings. In particular, the effect of multiple TBP repeats on coating efficacy and performance was examined.;Furthermore, the modularity of this platform has general applicability to the enhancement of medical implant performance. The peptide-based approach also allows for robust modification of material surfaces without the need for complex reaction schemes, and is therefore amenable to simple, point-of-care application in a surgical setting.