Enhanced biocompatibility and osseointegration properties of magnetron sputtered BTO-SZTO bio-piezoelectrically coated films as zirconium alloy implants

Abstract

Bio-piezoelectric materials were capable of improving the osseointegration properties of implants by converting mechanical forces into electrical signals that provided microelectrical stimulation for the formation and remodeling of bone tissue. Although metallic bioimplant materials can provide adequate mechanical strength, their surfaces were biologically inert as well as lacking the piezoelectric properties to stimulate osteogenesis. In this study, perovskite piezoelectric materials (BaTiO3–SrZrTiO3) were uniformly deposited on the surface of a low-modulus zirconium alloy by magnetron sputtering, which endowed the surface of metallic biomaterials with favorable piezoelectric properties. Orthogonal tests were used to optimize the magnetron sputtering process parameters for the preparation of piezoelectric coatings. The morphology and electrical properties of the coated films were characterized by XRD, XPS, SEM, AFM and SKPFM. The piezoelectric constant of the piezoelectric coating prepared in this study was 5.02 pC/N, which approximated the piezoelectric properties of natural bone tissue. Biological experiments showed that the BaTiO3–SrZrTiO3 piezoelectric coated film had a good promotion effect on the early adhesion, proliferation and differentiation of osteoblasts. Compared with the traditional metal implant materials, this innovative method successfully simulated the piezoelectric properties of bone tissue on the material surface, resulting in better osseointegration properties of metal biomaterials. This method will provide a proven solution for surface modification of metallic implant materials.