Vanillin-bioglass cross-linked 3D porous chitosan scaffolds with strong osteopromotive and antibacterial abilities for bone tissue engineering.

Chitosan scaffolds crosslinked by current methods insufficiently meet the demands of bone tissue engineering applications. We developed a novel effective crosslinking technique by using the natural and safe vanillin together with bioglass microparticles to generate an antibacterial, osteoconductive, and mechanically robust 3D porous chitosan-vanillin-bioglass (CVB) scaffold. In addition to the significantly improved mechanical properties, the CVB scaffolds had high porosity (>90%) and interconnected macroporous structures. Our data suggested that the crosslinking mainly resulted from the Schiff base reactions between the aldehydes of vanillin and amines of chitosan, together with the hydrogen and ionic bonds formed within them. Importantly, the CVB scaffolds not only showed good biocompatibility, bioactivity, and strong antibacterial ability but also significantly promoted osteoblastic differentiation, mineralization in vitro, and ectopic bone formation in vivo. Thus, the CVB scaffolds hold great promise for bone tissue engineering applications based on their robust mechanical properties, osteoconductivity, and antibacterial abilities.