Abstract
Infection around implanted biomaterials in humans is a major healthcare issue and current ability to effectively prevent and treat such infections using antibiotics is limited. The hypothesis of the study was that surface charge could be manipulated to a positive state and thus moderate bacterial adhesion to the implant. The surface charge was manipulated by creating a galvanic cell using a zinc strip in a standard suction drain.
Adhesion of Staph. aureus and Staph. Epidermidis to stainless steel and titanium implants in vitro and in vivo was quantified by sonication and log dilution technique. The response to this surface manipulation of charge varied for both the bacterial species and the type of metallic implant. In vitro studies produced an 88% reduction in Staph. aureus adhesion to stainless steel and a 36% reduction in adhesion to titanium. However Staph. epidermidis showed an increased adhesion to stainless steel (Log 1.81 ± 1.12 in vitro) and to titanium (log 1.80 ± 0.12). Staph aureus demonstrated a log increase of 1.56± 0.09 in adhesion to titanium in vivo while Staph. epidermidis generated a log increase of 3.97± 0.10 in adherent bacteria.
In this experiment we have shown that alteration of the electrochemical environment around an implant influences bacterial adhesion. While our technique is not therapeutically viable, further manipulation of surface charge of an implant is possible using other electroactive materials. This may be explored in the prophylactic treatment of implant infection
Abstracts prepared by Dr P E Watkins, Hodgkin Building, Guys Campus, King’s College London.
