Graphene/barium titanate/polymethyl methacrylate bio-piezoelectric composites for biomedical application

The introduction of BaTiO₃ (BT) particles into biomaterials, such as polymethyl methacrylate (PMMA) bone cement, is among the effective ways to improve their osteoinductivity. However, excessive addition leads to mechanical degradation. An important problem to solve is the manner by which piezoelectric properties matching human bones can be obtained under the premise of sufficient mechanical properties. The piezoelectric effect is obtained by adding BT particles into PMMA bone cement. The piezoelectric coefficient close to the human bone is obtained at a relatively low BT addition amount by adding graphene on this basis. High mechanical properties can also be obtained. Graphene increases the piezoelectric coefficient by increasing the conductivity, dielectric constant, and effective polarization voltage of graphene (G)/BT(BaTiO₃)/PMMA bio-piezoelectric composites. The compression strength of the aforementioned composites increases from 83.5 MPa to 89.5 MPa after the addition of 0.5 vol% graphene, and the requirements of bone implant materials were met. G/BT/PMMA bio-piezoelectric composites have no cytotoxicity, and graphene can also promote cell adhesion and proliferation on the composite's surface. The polarized bio-piezoelectric composites can improve cell morphology and promote cell proliferation. The number of cells increases with increasing piezoelectric coefficient. The composite has potential application prospects in various fields, such as oral cavity and bone implant.