Antibacterial effect of silver-modified implant materials

• Applicants: Dr. Jessica Meißner; Professor Dr.-Ing. Mirko Schaper
• Subject Area: Materials in Sintering Processes and Generative Manufacturing Processes ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 538437364

The proposed research project aims to develop iron-based materials with an antibacterial effect as innovative implant materials to prevent implant infections. Infections counteract the benefits of the implants and are associated with considerable patients burdens and follow-up costs. They are connected with biofilm growth on the implant surface, which protects the causative germs from the immune system and therapies. Even with high medical standards, an infection cannot be completely avoided. Thus, among others, the increasing spread of multi-resistant germs endangers progress in medical technology. Most of the currently used inert implant materials have been developed without considering the problem of infection. Therefore, various approaches to modify implants are increasingly being addressed, e.g. by releasing anti-bacterially effective silver ions. The scope of the proposed research project is to create near-surface phases of a degradable silver alloy within an inert iron-based implant material for an adapted release of silver to prevent infection. Low doses are sufficient as the ions are released directly at the target site thus, bypassing the shielding effect of the biofilm. The complete insolubility of iron and silver in each other enables the setting of these silver phases but makes processing challenging. Powder metallurgical processes, such as laser powder bed fusion (LPBF), enable the processing of powder mixtures of the individual material components. Thus, LPBF is applied to set adapted phases of a degradable, functional silver alloy at the surface of iron-based, inert material 316L, resulting in a targeted release of silver ions. Due to particle release from the alloy, biocompatibility studies are examined with different cell types like primary osteoblasts and cell lines (fibroblasts and endothelial cells) to study inflammation parameters and anomalies of cell metabolism. Furthermore, co-incubation experiments with bacteria and cells are planned to study the antibacterial effect in various infection scenarios.

• DFG Programme: Research Grants