Fabrication and Properties of Chitosan/Calcium Polyphosphate Fibre Composite Biological Scaffold

Natural biomaterials are widely used in the construction of cartilage tissue engineering due to their excellent biocompatibility, easy degradation, and ability to degrade products to be absorbed by the human body. However, due to their poor mechanical properties, it is usually necessary to composite them with other materials to prepare biological scaffolds that meet the expected requirements. This study used freeze-drying technology to introduce calcium polyphosphate fibres (CPPFs) into a chitosan (CS) matrix to prepare composite scaffolds with better performance. CPPF was used as a filler and inorganic skeleton in the CS/CPPF composite to improve the properties of the CS-based scaffold. With little change in porosity, the compressive strength of the CS/CPPF composite scaffold increased from 0.172 MPa of chitosan to 0.332 MPa with the increase in CPPF addition. The water absorption rate of the composite scaffold decreased from 1297.42% to 935.37%. In vitro degradation experiments revealed that CPPF accelerated the degradation of the scaffold and generated calcium phosphate and nano-hydroxyapatite compounds during the degradation process. According to our cytotoxicity testing, the CS/CPPF composite scaffolds exhibited good biocompatibility and could enhance cell proliferation. This method of incorporating CPPF into CS provides important reference values for the application of CPPF in other natural bone tissue engineering scaffold materials.