Project I: Prevention of total joint replacement infections

Department of Biomaterials
Coordinator: D Neut PhD MSc

Biomaterials (polymers, metals, or ceramics) are used more and more in modern medicine to replace, support or restore human body function, for example in joint prostheses, prosthetic heart valves or catheters. Application of these biomaterials bears one major drawback: the risk of attracting infectious bacteria. After adherence, bacteria encase themselves in a hydrated matrix of polysaccharides and proteins to form a slimy layer known as a biofilm. Biomaterial-related infections can cause severe problems, from disfunctioning of the implanted device to lethal sepsis of the patient. Furthermore, treatment of these infections is complicated, as bacteria in a biofilm are much more resistant to antibiotics than their planktonic counterparts. The best way to deal with this problem is to prevent the development of an infectious biofilm on the biomaterial surface.

To prevent biomaterial-related infections in orthopeadics, bone cement -used to anchor prostheses in joint replacement surgery- is loaded with antibiotics. However, several in vitro and in vivo studies indicated bacterial growth on these antibiotic-loaded bone cements, despite the high local antibiotic concentrations. This has stimulated interest in the incorporation of another antimicrobial or a second antibiotic into bone cement, so called multi-drug loading.

We are going to determine the effect of altering the commercially available antibiotic-loaded bone cements on biofilm formation. Biofilms of several clinical bacterial strains will be grown on bone cement samples, and these biofilms will be visualized using the confocal laser scanning microscopy (CLSM). We will also investigate the biofilms by determining the biomass, live/dead ratio of the bacteria and slime production.