| AVS 58th Annual International Symposium and Exhibition | |
| Biomaterial Interfaces Division | Wednesday Sessions |
| Session BI-WeM |
| Session: | Cells at Interfaces |
| Presenter: | Daniel Siegismund, Friedrich Schiller University Jena, Germany |
| Authors: | D. Siegismund, Friedrich Schiller University Jena, Germany A. Schroeter, Friedrich Schiller University Jena, Germany S. Schuster, Friedrich Schiller University Jena, Germany M. Rettenmayr, Friedrich Schiller University Jena, Germany |
| Correspondent: | Click to Email |
Biomaterials for implant purposes are increasingly applied in modern medicine e.g. to recover human body functions or for tissue substitution in general. Infections of these implants, called Biomaterial-centered infections (BCI), are among the fundamental challenges in biomaterials science. They are primarily initiated by adhesion of bacteria on the biomaterial’s surface. The subsequent formation of a bacterial biofilm requires a total implant replacement in the majority of cases.
The adhesion of bacteria is thus the first crucial step for biofilm formation that is only incompletely understood. Interactions of bacteria with the surface are controlled by surface properties such as surface energy, surface chemistry and topography.
In the present work, a model for bacterial adhesion is introduced that describes the early stages of biofilm formation as a function of the surface properties. A two-dimensional Cellular Automaton (CA) / Finite Difference (FD) adsorption model is combined with the predictions of the extended DLVO (Derjaguin, Landau, Verwey, Overbeek) theory that accounts for the interaction energies between the bacteria and the material’s surface. The model describes the mass transport of bacteria in an aqueous solution towards the material’s surface and the adsorption and desorption process, depending on the surface properties.
The adhesion process of different human pathogenic bacteria (Enterococcus faecalis, Staphylococcus aureus, Escherichia coli) on different biomaterial surfaces (titanium, stainless steel, polyethylene, polymethylmethacrylate, polytetrafluoroethylene) has been simulated. Results are the surface coverage with bacteria and, where applicable, clustering of the bacteria due to their migration on the surface.
Excellent agreement with experimental findings from the literature and own adhesion experiments concerning the kinetics of the adsorption process is found. In addition, a realistic bond strengthening mechanism of bacteria on surfaces, as described in the literature, is reproduced by the model. By using a spatial pattern analysis of our own experimental data we show that physical processes occurring during initial stages of the adhesion process are essentially correctly incorporated in the model.