Enhanced antibacterial and adhesive properties of chitosan/gelatin hydrogel containing berberine hydrochloride and prepolymerized gallic acid exhibiting aggregation-induced emission

Medical devices and human implant materials carry a risk of bacterial infection. Biocompatible and adhesive antibacterial materials that prevent biofilm formation are commonly used to reduce the risk. Herein, a crosslinked chitosan/gelatin (CG) hybrid hydrogel with antibacterial and adhesive properties was developed by introducing berberine hydrochloride (BBR) and adhesive prepolymerized gallic acid (PGA) to the hydrogel. BBR self-assembles into nanoparticles and imparts AIE function to hydrogels by intermolecular electrostatic interactions and p-p stacking. The hydrogel was used as a stable carrier for BBR. The antibiofilm performance against Escherichia coli and Staphylococcus aureus after light exposure increased from 20% and 30% (CG hydrogel) to 74% and 85% (CGBBRPGA hydrogel), respectively. When used as a photodynamic agent, the hybrid hydrogel exhibited enhanced antibacterial and antibiofilm capabilities against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. The CGBBRPGA hydrogel showed strong adhesion to the surfaces of pig skin (9.2 kPa), glass (7.6 kPa), steel sheet (5.8 kPa), and PEEK sheet (5.5 kPa). Furthermore, it exhibits cell adhesion and shows negligible cytotoxicity, which indicates its cytocompatibility. Consequently, the fabricated hybrid hydrogel offers potential applications in biomedicine, particularly in wound dressing and surface modification of medical implants.