Device associated infections (DAI), together with incompatibility reactions and surgical deficiencies are the main reasons for failure of modern medical devices in practice, often with severe consequences including high distress for the patients and huge socio-economical costs. We identified device applications in a variety of medical domains, such as cardiovascular, orthopedics, trauma, urinary incontinence, and ophthalmology in which DAI rates range from 2 to 40%. The costs for revision of infected devices are dramatically increasing the original implantation costs. Despite a substantial increase in recent research efforts on antibacterial strategies, there is currently no effective clinical solution. The few antimicrobial active compound containing devices rely on delivery of massive amounts of antibiotics, or on the release of silver which is limited to topical applications.
The main objective of this project is to engineer “self-defending” polymer surfaces with a dual functionality based on: 1.) stealth polymer membranes with appropriate topology (passive strategy) and 2) association with immobilized nanoreactors releasing antibiotics “on demand” (active strategy). The primary goal our joint collaboration intends to overcome is the complexity of research projects in this field requires a highly complementary team containing expertise across chemistry, physics, nanoscience, and biology. Therefore, we propose combining the research field and infrastructure of the Swiss research unit at the University of Basel (Cornelia G. Palivan and Wolfgang Meier groups), in the field of polymer synthesis and development of nanoscale hybrid systems, together with the surface architecture control expertise of our Chinese partner at the Institute of Chemistry, Chinese Academy of Sciences (Jian Xu group).
We plan a bottom-up approach to support the synthesis and investigation of various amphiphilic copolymers for the development of controlled bio-responsive surfaces serving to efficiently fight against DAI. The focus will be on aqueous self-assembly, “grafting-to” approaches, as cost-effective ways to exploit biomimetic and strong multivalent adhesion. First, surface properties after coating with polymer membrane will be controlled by the surface chemical composition, and by an artificially generated biomimetic microstructure inducing a modification of interface interactions. Second, polymer compartments containing antibiotics will be immobilized on polymer coated surfaces by strong covalent interactions of molecular recognition interactions. Finally, antibacterial assays will distinguish the simultaneous impact of surface morphology, architecture, and release of antibiotics on the bio-responsive properties.
An expected benefit of the joint research project will be improving protection against DAI by biomaterials/surfaces with dual functionality and improved long-term stability. In addition, the establishment of comprehensive sets of standard test methods with appropriate reference materials will allow for comparison of outcomes and optimization of the antibacterial activity of our “self-defending” surfaces. Our Swiss-Chinese research teams will unify their efforts for an important experimental contribution to the field of multifunctional bio-responsive surfaces with applications in medical technology.