Bioceramics Working Group
The bioceramics working group at the Institute of Mineral Engineering deals with the development of novel ceramic materials for medical use. The focus is on inert high-performance ceramics such as Al2O3, ZrO2, non-oxide ceramics, in particular, SiC and Si3N4, as well as calcium phosphate-based materials with bioactive or bioresorbable properties. An important aspect of the development work is a customized surface conditioning of the above-mentioned materials since the most decisive in vivo processes take place on the surface immediately after implantation. In addition, the research group concentrates on multifunctional materials that exhibit several biological characteristics such as osseointegration, osseoinductance, hemocompatibility, bactericity, etc. and which could thus ensure improved implant integration in the body with a minimized risk of infection.
Investigation of non-thrombogenic bioceramics for cardiovascular implantsCopyright: © GHI
Cardiovascular diseases (CVD) involve any symptom which affects the heart and blood vessels. For many of the CVD patients, surgical treatment is considered as the only effective solution. This treatment involves either restoration or substitution of the damaged part with a biomedical implant. However, biomedical implants can give rise to thrombosis problems and the patients might face a risk of hemorrhage due to the chronic anticoagulation therapy for blood coagulation.
The current research focuses on the investigation of non-thrombogenic ceramics surfaces for cardiovascular implants, which reduce the anticoagulation usage of the patients and consequently prevent bleeding risks. In order to develop implants with improved hemocompatibility, it is particularly important to understand the thrombosis mechanism at the biomaterial/blood interface. As being promising biomaterials, single-crystalline ceramics (Al2O3, ZrO2, SiC) are investigated in terms of their cytocompatibility, endothelialization quality, and blood cell responses. Different surface properties of ceramics, such as crystallographic orientation, surface plane, and atomic arrangement are considered. We perform static and dynamic cell culture experiments, cell morphology characterization, and several quantitative and qualitative biological analyses in cooperation with partner institutions.
CeramStent: Research into hemocompatible ceramic-metal composite coatings for cardiovascular applications.Copyright: © GHI
Metal-based vascular stents are considered the gold standard in cardiology and are used to to improve the patency of arteriosclerotically narrowed coronary vessels.However, the high mortality rate among patients with coronary heart disease shows, that the requirements for the materials used in this area have not yet been fully met. The main objective of the research is to develop a reproducible, tailor-made coating with hemocompatible properties for long-term medical use on cardiovascular implants. The coating is designed to improve hemocompatibility and significantly increase the service life of the materials used to date.
Supported by the German Research Foundation (DFG) - 405895710
Surface functionalization of ceramic implantsCopyright: © GHI
The surface quality is crucial during the first phase of an implantation. It depends on complex processes whether the implant is absorbed by the body or rejected. By modifying the surface, these reactions could be influenced by a specific surface design, depending on the application and field of application.
This can be achieved, for example, by covalent immobilization of a monolayer of graphene oxide on an activated ceramic surface, since this material exhibits both antimicrobial and osteoinductive as well as haemocompatible properties. In addition, the material shows efficient amounts of reactive carboxyl, hydroxyl and epoxy groups due to a large specific surface area. These can play a decisive role for subsequent loading with biologically active components such as growth factors or short peptide sequences.
Calcium phosphate (CaP) based materials are used as bone replacement implants due to their bioactive and partly bioresorbable properties. Due to their mechanical properties, their use is limited to non-load-bearing bone defects. These materials are nevertheless suitable as coatings on inert ceramic implants. The biocompatible CaP coating can be multifunctionalized with various biological components such as proteins or antibiotics by co-deposition, as is the case with graphene oxide films.