Polydopamine-Assisted Anchor of Chitosan onto Porous Composite Scaffolds for Accelerating Bone Regeneration

Surface function has an importance for the bioactivity of porous polymeric scaffolds. The goal of the present study is to immobilize highly bioactive chitosan (CS) onto the surface of porous composite scaffolds to accelerate bone regeneration. Porous poly(ε-caprolactone) (PCL)/bioactive glass (BG) composite scaffolds with strong anchor of CS were fabricated via mussel-inspired polydopamine (PDA) coating as a bridging layer. In vitro cell culture showed that firm immobilization of CS onto the composite scaffolds significantly enhanced protein adsorption, cell adhesion, and osteogenic differentiation compared to CS-decorated scaffolds via physical adsorption. In vivo assessments demonstrated that covalent immobilization of CS onto the surface of scaffolds obviously promoted cranial bone regeneration in comparison with the counterparts with physical adsorption of CS. The proposed method offers a feasible and effective means to fabricate artificial bioactive scaffolds for bone tissue engineering application.