Hybridization of graphene oxide and mesoporous bioactive glass: Micro-space network structure enhance polymer scaffold

Graphene oxide (GO) and mesoporous bioactive glass (MBG) are commonly used to improve the mechanical and biological properties of polymer scaffolds, respectively. Nevertheless, their single introduction to polymers may encounter problems with uneven dispersion due to nano-aggregation effects. In this work, a GO and MBG hybrid with micro-space network structure were prepared by a chemical reduction-coagulation method to solve these problems. GO and MBG were first uniformly mixed in an alkaline aqueous dispersion. Subsequently, GO was partially reduced by introducing dopamine and co-coagulated with MBG, and then assembled into a GO@PDA@MBG hybrid structure under electrostatic effect. Specifically, the ring opening and deoxygenation reaction between the oxygen-containing functional group of GO and the amine group of dopamine achieves functionalization and partial reduction of GO. In addition, the hydrogen bond between the amine group of dopamine and the silanol hydroxyl group of MBG promotes the coagulation of MBG on GO@PDA. The hybrid structure was then mixed into polymer matrix to prepare a composite scaffold by a laser additive manufacturing process. The results showed that GO @ PDA @ MBG hybrid structure increased the tensile strength and modulus of polymer scaffold from 5.8 MPa and 312.2 MPa to 14.1 MPa and 539.7 MPa, respectively. The enhanced mechanical properties can be attributed to the pinning and crack strengthening effect of GO@PDA@MBG hybrid structure in polymer matrix. Besides, the scaffold also significantly promotes adhesion and proliferation of osteoblasts, demonstrating good biological properties.