Binding of teicoplanin and vancomycin to polymer surfaces.

Both teicoplanin and vancomycin were found to bind to a range of polymer surfaces. The binding of teicoplanin to specimen vessel surfaces was, on average, four times greater than that of vancomycin and was particularly marked with silconized polymers (5.2 micrograms/cm2). Pre-exposure of a polymer surface to human body fluids caused a 60% reduction in teicoplanin binding. Reduction of the negative surface charge on a polymer surface with ferric nitrate resulted in a ten-fold increase in teicoplanin binding. The accumulation of a strain of Staphylococcus epidermidis on silicone rubber catheter segments pre-exposed to glycopeptide antibiotics was examined. In phosphate buffered saline binding of bacteria to vancomycin-treated polymer was greater than to an unexposed control surface. In contrast, in human serum both antibiotics caused reductions in adherent growth. The binding of glycopeptide antibiotics, in particular teicoplanin, to polymer surfaces may interfere with the results of in-vitro assays. However, this phenomenon may be useful in the prevention of bacterial accumulation on the surfaces of medical devices.