Fabrication and in vitro biological properties of piezoelectric bioceramics for bone regeneration

The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO₃) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d₃₃ of HA/BaTiO₃ piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO₃ content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO₃ piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO₃ promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO₃ piezoelectric ceramics.