Construction of natural AIEgens-embedded chitosan network coatings with synergistic antibacterial effects

Implant-associated infections (IAIs) pose a serious complication of implant surgeries, and the overuse and misuse of antibiotics to treat these infections can lead to the emergence of drug-resistant bacteria. To address this problem, the development of non-antibiotic antibacterial coatings for biomedical materials is imperative. In recent years, there has been a growing interest in utilizing aggregation-induced emission luminogens (AIEgens) for antibacterial photodynamic therapy (APDT). However, the utilization of AIEgens in the surface modification of biomaterials to combat bacterial infections has been rarely reported. In this work, a natural AIEgen, berberine (BBR), was encapsulated into a polymer network of phytic acid (PA) and carboxymethyl chitosan (CMCS). The resulting PA-CMCS-BBR (PA-CB) aggregates are conveniently deposited onto solid materials in a substrate-independent manner. Furthermore, the PA-CB coating allows for a controlled release of BBR, which has an anti-inflammatory effect. The PA-CB-modified surfaces demonstrate good biocompatibility and exhibit synergistic antibacterial effects upon exposure to white light irradiation. These findings are expected to contribute to the development of advanced antibacterial coatings for biomedical applications.