Plant-bergenin derived biofunctionalization of titanium surface with enhanced activity against biomaterial associated pathogen

Implant-associated bacterial infections remain a major challenge in biomaterials research, highlighting the need for effective and biocompatible strategies to prevent bacterial colonisation at implant surfaces. This study investigated the antibacterial potential of four phytochemicals—bergenin (B), norbergenin (NB), galloyl-lawsoniaside (GL), and uromyrtoside (U)—isolated from an Australian wet tropical endemic plant and evaluated the potential of bergenin as a biofunctional coating for titanium surfaces. The antibacterial activity of the phytochemicals against Staphylococcus aureus and Pseudomonas aeruginosa was assessed using zone of inhibition (ZOI), optical density (OD 600 ), and colony-forming unit (CFU/mL) assays across concentrations of 150–1000 μg mL -1 . All phytochemicals demonstrated concentration-dependent antibacterial activity, with S. aureus generally exhibiting greater susceptibility than P. aeruginosa . Against P. aeruginosa , the estimated IC 50 values were 220, 232.4, 240, and 233.1 μg mL -1 for B, NB, GL, and U, respectively, whereas S. aureus exhibited IC 50 values of 150 μg mL -1 for B, NB, and GL, and 733 μg mL -1 for U. Among the tested compounds, bergenin demonstrated the strongest antibacterial activity, producing a ZOI of ≥21 mm at 1000 μg mL -1 and up to 91% inhibition of bacterial growth based on OD 600 measurements (p < 0.05). CFU analysis further confirmed substantial reductions in bacterial viability, with plant-derived bergenin achieving approximately 95% bacterial reduction and outperforming its commercial counterpart. Importantly, bergenin-functionalised titanium surfaces demonstrated >90% reduction in bacterial viability against S. aureus after 24 h, confirming effective surface-mediated antibacterial activity. Collectively, these findings identify bergenin as a promising plant-derived antibacterial phytochemical and demonstrate its potential as a biofunctional surface modifier for developing infection-resistant titanium biomaterials. This multifunctional approach provides a promising platform for improving the antibacterial performance of titanium implant surfaces while supporting the development of plant-derived strategies for infection prevention.