Facile one-step bioinspired mineralization by chitosan functionalized with graphene oxide to activate bone endogenous regeneration

[Display omitted] •Bioinspired GO/CS/nHAP scaffold was fabricated by facile one-step in situ method.•nHAP achieved uniform dispersion into covalent GO/CS network matrix.•The cellular microenvironment was improved by integrating GO with nHAP into CS.•The biomineralization of scaffold in SBF proved distinguished bioactivity.•Prepared scaffold could induce bone tissue endogenous regeneration in situ. Facilitated endogenous tissue engineering is emerging as a convenient and easy strategy for bone repair. However, the substitution with satisfactory bioactivity and osteoinductivity which can activate endogenous stem cells responds and in situ recruit them homing towards to damaged area remains a challenge. To stimulate the biomineralization process of inorganic nanoparticles in natural bone, bioactive nano hydroxyapatite particles (nHAP) were in situ crystallized into the graphene oxide/chitosan/nHAP (GO/CS/nHAP) scaffold via effective regulation of CS functionalized with GO network matrix and presented a uniform dispersion with nanometer-scale. As-prepared scaffold exhibited better physicochemical properties, such as three-dimensional (3D) porous bone-like hierarchical structure, proper mechanical property, biodegradation as well as suitable water uptake and retention ratio. The biomimetic mineralization and cell culture experiments demonstrated that hybrid scaffold possessed superior bioactivity and cell proliferation ability in vitro. In addition, the rat calvarial defect repair models and tissue pathological characterization further proved that the hybrid scaffold had excellent biocompatibility and capacity of in situ inducing bone regeneration. Herein, the prepared scaffold might be an excellent candidate for endogenous bone repair.