Advanced Dual-Functional Surface Coatings for Microbial Resistance and Enhanced Biocidal Action

• Applicants: Professorin Dr. Ruth Freitag; Dr. Günter Motz
• Subject Area: Biomaterials ; Coating and Surface Technology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 578416343

Infections caused by multi-drug-resistant pathogens pose an increasingly serious threat to patients and hospital staff. The development of multi-drug-resistant "superbugs" due to excessive antibiotic use has contributed significantly to this problem. Surfaces and medical instruments play a key role in transmission, so the effectiveness of standard disinfection practices is increasingly being questioned. The development of novel, long-lasting antimicrobial coatings is therefore of great importance. The aim of this project is to develop a novel bifunctional, robust antibacterial coating system, particularly for use in healthcare. The dual coating consists of a dense upper superhydrophobic layer based on polysilazanes. This prevents biofilm formation and facilitates easy cleaning and decontamination. Fillers such as glass and ceramics allow for fine-tuning of the functional and mechanical properties. The underlying biocidal layer is based on metal-modified (Zn2+, Cu2+, and Ga3+) polysilazanes and eliminates bacteria in the presence of defects in the upper layer. This innovative combination is expected to significantly improve the longevity and reliability of antibacterial coatings. In the past, antibacterial properties were often discovered by chance or simple trial and error, without considering the underlying mechanisms or the role of different bacterial species. This complicates systematic development, particularly with regard to preventing resistance. Effective antibacterial coatings must also prove their effectiveness in practice against bacterial consortia. Their development should therefore not be validated exclusively with pure strains and should go beyond the determination of mortality rates such as the LD50. Studies of various bacterial species, including those that form protective biofilms, should provide valuable insights for the iterative improvement of coating properties. Investigating the cellular response at the transcriptome and proteome levels is of utmost importance in identifying targeted targets that can be exploited for precise antimicrobial action. The project's interdisciplinary approach, which combines materials science and bioprocess engineering, enables a systematic evaluation of coating functions, considering the potential for bacterial resistance. Ultimately, this project aims to provide crucial insights for the development of durable, antibacterial coatings for use in healthcare and expand our understanding of the interactions between bacteria and antibacterial materials.

• DFG Programme: Research Grants