Nanostructure Mediated Piezoelectric Effect of Tetragonal BaTiO(3) Coatings on Bone Mesenchymal Stem Cell Shape and Osteogenic Differentiation

In recent years, porous titanium (Ti) scaffolds with BaTiO(3) coatings have been designed to promote bone regeneration. However, the phase transitions of BaTiO(3) have been understudied, and their coatings have yielded low effective piezoelectric coefficients (EPCs < 1 pm/V). In addition, piezoelectric nanomaterials bring many advantages in eliciting cell-specific responses. However, no study has attempted to design a nanostructured BaTiO(3) coating with high EPCs. Herein, nanoparticulate tetragonal phase BaTiO(3) coatings with cube-like nanoparticles but different effective piezoelectric coefficients were fabricated via anodization combining two hydrothermal processes. The effects of nanostructure-mediated piezoelectricity on the spreading, proliferation, and osteogenic differentiation of human jaw bone marrow mesenchymal stem cells (hJBMSCs) were explored. We found that the nanostructured tetragonal BaTiO(3) coatings exhibited good biocompatibility and an EPC-dependent inhibitory effect on hJBMSC proliferation. The nanostructured tetragonal BaTiO(3) coatings of relatively smaller EPCs (<10 pm/V) exhibited hJBMSC elongation and reorientation, broad lamellipodia extension, strong intercellular connection and osteogenic differentiation enhancement. Overall, the improved hJBMSC characteristics make the nanostructured tetragonal BaTiO(3) coatings promising for application on implant surfaces to promote osseointegration.