Balancing hydrophobicity and surface potential in bio-based bisfuran-containing polyamide coatings for enhanced long-term antibacterial efficacy and endotoxin adsorption

To develop antimicrobial protective materials based on renewable polymers, we synthesized a series of bio-based bisfuran-based polyamide (bFPA) polymers with various functional groups, including allyl quaternary ammonium cations, decyl quaternary ammonium cations, and sulfonate betaine. These bFPA-based coating materials, featuring excellent thermal stability (>230 °C) and biocompatibility, were facilely fabricated on polyurethane (PU) substrates by blending and crosslinking with unsaturated aliphatic PU resin. By altering the combination of different functional groups in bFPA polymers, we controlled the hydrophilicity/hydrophobicity and surface charge properties of the bio-based coating. Compared to pure PU coatings, the bFPA-based coatings with moderate hydrophilicity/hydrophobicity and surface potential significantly reduced the adhesion of model protein and bacteria by approximately 70 % and >99 %, respectively, demonstrating outstanding anti-protein and anti-bacterial adhesion properties. Even after seven cycles of use, the coatings maintained the ability to kill ∼80 % and >99 % of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, respectively, indicating long-lasting antibacterial activity. Additionally, the optimized bFPA-based coatings effectively adsorbed ∼80 % of endotoxins from damaged Gram-negative bacteria through electrostatic interactions, thereby reducing the risk of inflammation and sepsis. The development of bio-based polyamide coatings with long-term antibacterial and endotoxin adsorption properties significantly advances their safe and reliable application of in the field of biomedical devices.