| Infection of implanted materials occurs by two important steps: adhesion of the bacteria to the material surface and colonization of the material by proliferation of bacteria on the material surface. Functionalized polyurethanes were synthesized and the effects of polyurethane chemistry on protein-mediated bacterial adhesion were studied. A protocol was developed to study bacterial proliferation on the polyurethanes and the potential antibacterial activity of the polyurethanes was examined.;When bacterial adhesion to bare polyurethanes was compared, the quaternized amine polyurethanes showed the highest levels of adhesion while the phosphonated Pellethane and zwitterionic phosphonated polyurethane showed the least amount of adhesion. The high levels of adhesion on the quaternized polymers were likely due to the ionic interactions between the quaternized amine moiety and the bacterial cell membrane. Treatment of the polyurethanes with increasing concentrations of fibrinogen resulted in at least ten-fold increases in adhesion on Pellethane, sulfonated Pellethane, phosphonated Pellethane, and the zwitterionic phosphonated polyurethane. The quaternized amine polyurethanes, which showed the highest adhesion in the absence of fibrinogen, exhibited relatively small increases in adhesion when treated with fibrinogen.;The effect of two-chain high molecular weight kininogen (TCHMWK) on fibrinogen-mediated adhesion was studied. When samples were treated with fibrinogen then TCHMWK, decreases in adhesion relative to samples treated only with fibrinogen were observed on Pellethane, sulfonated Pellethane, phosphonated Pellethane, and the zwitterionic phosphonated polyurethane, but not on any of the quaternized amine polyurethanes. The decrease in adhesion was likely due to TCHMWK displacing the fibrinogen from the polymers.;Bacteria were able to colonize Pellethane, sulfonated Pellethane, and phosphonated Pellethane in both the presence and absence of albumin. Iodide-containing quaternized amine polyurethanes, the cadmium-containing zwitterionic phosphonated polyurethane, and stabilized silver-containing Pellethane were bactericidal whether or not albumin was present. A chloride-containing quaternized amine polyurethane lost some of its bactericidal character when coated with albumin. This suggested that the presence of a releasable antimicrobial is an important factor in preventing bacterial colonization. |
