Enhanced compressive strengths and induced cell growth of 1-3-type BaTiO3/PMMA bio-piezoelectric composites.

Barium titanate (BaTiO3) has been used as a bone implant material because of its piezoelectric properties and the ability to promote cell growth when combined with hydroxyapatite. However, the brittleness of BaTiO3 inhibits its use as a bone replacement material at load-bearing sites, and the reduction of BaTiO3 content in the composite reduces its piezoelectric effect on bone growth. In this study, we explored a preparation method, which included directional freeze casting and self-solidification of bone cement, to obtain 1-3-type BaTiO3/PMMA bio-piezoelectric composites with a lamellar structure. The lamellar BaTiO3 layer through the composite from the bottom to the top significantly improved the piezoelectric properties of the composite. In addition, the dendritic ceramic bridges on the BaTiO3 pore walls can improve the compressive strength and elastic modulus of BaTiO3/PMMA bio-piezoelectric composites with a lamellar structure. More importantly, it was found that polarized lamellar BaTiO3 could induce osteoblasts to grow in the direction of the BaTiO3 layers. When the width of the BaTiO3 layer was in the range of 8-21 μm, osteoblasts along the BaTiO3 layer showed well growth, which can be of great value for the production of biomimetic bone units.