Synthesis and precision casting of bioactive glasses and the impact of the microstructured surfaces on cellular behaviour

• Applicants: Professor Dr.-Ing. Andreas Bührig-Polaczek; Professor Dr. Reinhard Conradt; Professor Dr.-Ing. Horst Fischer
• Subject Area: Biomaterials ; Coating and Surface Technology
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 245108579

The aim of the project is to synthesise and microstructure bioactive glasses using precision casting to investigate the complex interactions between a bioactive/bioresorbable surface of an implant material and neighbouring cells regarding a subsequent in vivo application.In a pilot study the three working groups (ZWBF, GI, GHI) have investigated the structuring of bioactive glass by the use of casting techniques. A glass matching the composition of Bioglass 45S5 (Hench glass) was synthesized and manually casted in a ceramic mould with a lamellar structure of 120 µm. The casted specimens proved that in principle precision casting is suitable for the manufacturing of glass bodies with a microstructured surface. Yet, accuracy and mould removal are still an issue. Therefore, further research activities have to focus on glass synthesis, mould manufacturing and the casting technology.In the applied project, glasses of the Na2O-CaO-SiO2-P2O5 system, established for clinical use, will be synthesized in combination with additional biologically stimulating elements, e. g. potassium and strontium. The impact of glass composition and surface structure on cell interaction will be investigated in detail. Precision casting will be applied to shape glasses with a specific microstructure. Various moulding techniques to obtain microstructures in different scales will be investigated. The mould materials will be analyzed regarding wettability and reactivity with the bioglass melts. The analyzation will be supported by computer assisted simulations. The surface structures will be adjusted to control the cellular response. Therein the particular focus is the osteogenic stimulation of bone-building cells by specifically designed microscopic structures. The corrosion behaviour of the surfaces will be analyzed under aqueous as well as physiological conditions and the underlying physical mechanisms are investigated. The objective of the research project is to evaluate all aspects relevant for the surface structure of a bioactive/resorbable glass implant with respect to the applied materials, the production process and the biological impact.

• DFG Programme: Research Grants