pH-Responsive Dopamine-Grafted Polysaccharide Hydrogel with Enhanced Antibacterial and Hemostatic Properties

Polysaccharide hydrogels crosslinked via Schiff base linkages demonstrate significant potential in drug delivery and tissue engineering. In this study, carboxymethyl chitosan (CMC) and dopamine-grafted oxidized hyaluronic acid (DA-OHA) were employed as active components to fabricate a composite hydrogel with significant pH responsiveness and excellent antibacterial and hemostatic capacities. The hydrogel formed a reversibly crosslinked network through the synergistic combination of Schiff base reactions and multiple hydrogen bonds. The porous morphology, swelling behavior, stimuli-responsive release behavior, adhesive, antibacterial, and hemostatic performances of the hydrogel were comprehensively evaluated. Results demonstrated that the optimal hydrogel fabricated with a CMC-to-DA-OHA mass ratio of 3:1 possessed favorable pH-dependent swelling and tunable drug release profiles, wherein drug release was enhanced at pH 6.0 in comparison with that at pH 7.2 and 8.0. Dopamine modification endows hydrogels with improved tissue adhesion, antibacterial capacity, and hemostatic performance. The optimized hydrogel achieves an adhesion strength of approximately 11.8 kPa, exhibits antibacterial rates above 97% against Staphylococcus aureus and Escherichia coli, and reduces blood loss by 93.3%, corresponding to only 6.7% of the blood loss in the control group. The as-prepared pH-responsive dopamine-grafted polysaccharide hydrogel possessing enhanced antibacterial and hemostatic functionalities exhibits great potential as a tissue engineering scaffold for wound healing.