Modified chitosan/oxidized carrageenan composite hydrogels incorporated with sea cucumber protein peptides as a potential novel biomedical material.

Facing the challenges of bacterial infection and antibiotic resistance, the development of biomaterials with both excellent antibacterial properties and biocompatibility is of great significance. Using chitosan (CS) and κ-carrageenan (Car) as raw materials, tris(hydroxymethyl)methylglycine-modified chitosan (CS-TMG) and oxidized carrageenan (O-Car) were respectively synthesized. And then by incorporating sea cucumber protein peptides (SPH), a multi-network CS-TMG/O-Car/SPH hydrogel was successfully prepared. Characterization by UV, FTIR, 1H NMR, XPS and XRD confirmed the successful grafting of TMG onto CS, the formation of aldehyde groups in Car, and the network structure stabilized by dynamic imine bonds and multiple physical interactions. CS-TMG/O-Car/SPH hydrogel exhibited a lamellar porous morphology and a high swelling ratio (2199%), coupled with good self-healing properties, injectability, and sustained-release characteristics (73.12% of SPH cumulative release within 72 h). Antibacterial tests revealed that CS-TMG/O-Car/SPH possessed significant antibacterial activities against both Staphylococcus aureus and Escherichia coli. Assessment of the biosafety revealed that CS-TMG/O-Car/SPH had a low hemolysis rate and negligible cytotoxicity, showing excellent biocompatibility. Consequently, CS-TMG/O-Car/SPH hydrogel is a promising candidate as an antibacterial biomaterial in the fields of wound healing and tissue engineering.