A simultaneously antimicrobial, protein-repellent, and cell-compatible surface-attached polymer network is reported, which reduces the growth of bacterial biofilms on surfaces through its multifunctionality. The coating was made from a poly(oxonorbornene)-based zwitterion (PZI), which was surface-attached and cross-linked in one step by simultaneous UV-activated CH insertion and thiol-ene reaction. The process was applicable to both laboratory surfaces like silicon, glass, and gold and real-life surfaces like polyurethane foam wound dressings. The chemical structure and physical properties of the PZI surface and the two reference surfaces SMAMP ("synthetic mimic of an antimicrobial peptide"), an antimicrobial but protein-adhesive polymer coating, and PSB (poly(sulfobetaine)), a protein-repellent but not antimicrobial polyzwitterion coating were characterized by Fourier transform infrared spectroscopy, ellipsometry, contact angle measurements, photoelectron spectroscopy, swellability measurements (using surface plasmon resonance spectroscopy, SPR), zeta potential measurements, and atomic force microscopy. The time-dependent antimicrobial activity assay (time-kill assay) confirmed the high antimicrobial activity of the PZI; SPR was used to demonstrate that it was also highly protein-repellent. Biofilm formation studies showed that the material effectively reduced the growth of Escherichia coli and Staphylococcus aureus biofilms. Additionally, it was shown that the PZI was highly compatible with immortalized human mucosal gingiva keratinocytes and human red blood cells using the Alamar Blue assay, the live-dead stain, and the hemolysis assay. PZI thus may be an attractive coating for biomedical applications, particularly for the fight against bacterial biofilms on medical devices and in other applications.

The possibility for unselective C–H activation of a thiophene-based, donor–acceptor–donor monomer during direct arylation polycondensation is investigated.

Supramolecular polymers are formed through non-covalent, directional interactions between monomeric building blocks. The assembly of these materials is reversible, which enables functions such as healing, repair, or recycling. However, supramolecular polymers generally fail to match the mechanical properties of conventional commodity plastics. Here we demonstrate how strong, stiff, tough, and healable materials can be accessed through the combination of two metallosupramolecular polymers with complementary mechanical properties that feature the same metal-ligand complex as binding motif. Co-assembly yields materials with micro-phase separated hard and soft domains and the mechanical properties can be tailored by simply varying the ratio of the two constituents. On account of toughening and physical cross-linking effects, this approach affords materials that display higher strength, toughness, or failure strain than either metallosupramolecular polymer alone. The possibility to combine supramolecular building blocks in any ratio further permits access to compositionally graded objects with a spatially modulated mechanical behavior.

Surfaces coated with polyzwitterions are known to resist protein adhesion and to be generally bio‐inert. In recent reports, several polyzwitterionic coatings with carboxylate groups and intrinsic antimicrobial activity due to the pH‐responsivity of that group are described, but the design rules to obtain such activity remain unclear. Therefore, in this work, a set of surface‐attached polyzwitterions with carboxylate groups and varying alkyl residues is studied. The gradually increasing hydrophobicity of these surfaces (verified by contact angle and swellability measurements) has an impact on their biological properties. Hydrophilic surfaces (polyzwitterions bearing short alkyl residues) behave like “classical” polyzwitterions: they repel proteins and human cells and are non‐toxic to bacteria. The more hydrophobic polyzwitterionic surfaces are protein‐adhesive, cell‐toxic, and can kill bacteria. This indicates that the hydrophobicity of polyzwitterionic surfaces needs to be balanced precisely to combine protein‐repellency and antimicrobial activity in a single material.