Chitosan-collagen composite biomaterials: Advances and insights into properties and biomedical applications.

Chitosan polysaccharides and collagen, derived from natural products, are important macromolecular compounds with extensive applications in many fields. In the past decade, substantial progress has been made in studying chitosan-collagen (CS-Col) composite biomaterials. Based on the morphology of materials, this work systematically reviews CS-Col composite biomaterials including nanoparticles, nanofibers, hydrogels, three-dimensional (3D) bioprinting scaffolds, films, and sponges. CS-Col composite biomaterials possess a range of unique properties including biocompatibility, antibacterial, antioxidant, hemostatic effects, promoting wound healing, and immune regulation. This review also summarizes advances in the applications of CS-Col composite biomaterials in medical fields, and provides insights into the challenges on future developments, as well as the prospects with the frontier technologies (e.g., 4D bioprinting, artificial intelligence-driven material design).