Analysis and simulation of electrical interactions of implants with bio-systems (WELISA).

Analysis and simulation of electrical interactions of implants with bio-systems (WELISA).

An important aspect of the development of biofunctional implant surfaces is a better understanding of the influence of micro- and nanastructured materials on cells growing on surfaces. The theoretical analysis of the adhesion is limited to adult cells. But it is known that the accretion of the cells happens in two phases. One is the passive phase containing the adhesion and migration of the cell depending to the properties of the surface.

The second phase is considerable longer and is defined by the metabolism of the cell. But the metabolism and the signal processing are also influenced by the surface design, what was shown with an example dealing with the cytoskeleton. Additionally to this theoretical work, statistical models and correlation analysis of the surface and the resulting cell properties exists. The combination of theses previous work and present experimental observations given from projects A1 und A4 can be used as a starting point for the planned theoretical analysis. By using the experimental results of cell growth as a function of the structured implant surface, a mathematical model should be developed. The surface properties will be a parameter of this model. It was shown that the surface structure of titan have influence on the expression of β3-Integrin receptor. The β3-Integrin receptor forms a focal adhesion to the observed titan surface structure (Lüthen et.al.(2005): "The Influence of Surface Roughness of Titaniumon β1- and β3- Integrin Adhesion and of the organisation of fibronection in human osteoblastic cells", Biomaterials, Vol. 26, pp. 2423-2440).

Illustration of the attachment of a cell to a biomaterial. The primary receptor for the adhesion of the cell to the environment, integrin, bounds to the extracellular matrix, which is contacted to the surface of the biomaterial. The receptor is bound to different intracellular signalling pathways, f.i. MAPK or actin polymerization. The attachment of the cell to a surface is therefore a regulatory process for a number of cell functions.

This process is induced by different signal transduction pathways. For a birdeye view see the KEGG-Pathway for focal adhesion. The mechanism are not or only poorly understood (Nebe et.al.(2007):"Interface Interactions of Osteoblasts with Structured Titanium and the Correlation between Physiochemical Characteristics and Cell Biological Parameters", Macromol. Bioscience, Vol. 7, pp. 657-578). The research of the Welisa group deals with the analysis and simulation of the electrical interactions of implants with biosystems (for more information visit the offical Welisa website). The aim of project A7 is the mathematical modelling of the cell reactions in dependance to the structure of the titanium surface. This will include the influence to the cell cycle, the actin polymerisation and the expression of the Integrin receptors. The project A7 is interconnected to projects A1, A3, A4 and A6 of the Welisa group.

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http://www.welisa.uni-rostock.de