Synthesis, Characterization and Bioactivity Evaluation of Porous Barium Titanate with Nanostructured Hydroxyapatite Coating for Biomedical Application

Abstract

AbstractNano phase hydroxyapatite (HA) bioceramics have gained importance in the biomedical field due to their superior biological properties. In this study, nanostructured HA coating was used to increase the bioactivity of a piezoelectric bioceramic, barium titanate (BT). Early reports on the influence of collagen piezoelectricity in remodeling of bone have attracted many researchers to piezoelectric bioceramics such as BT. Hence; porous BT was used as the matrix of a new bone graft composite and then coated with nanostructured HA. BT ceramic was foamed via a direct foaming method with a spray of polyurethane foam. The surface of the foam voids was coated with HA via sol–gel and dip‐coating methods. X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) techniques were used to characterize the prepared coated foam. XRD and TEM analysis showed that the HA coating had a nanostructure with crystallite size of 20–30 nm. SEM images of the prepared samples showed that the HA coating has about 25 µm thickness. The bioactivity of the prepared composite was evaluated in an in vitro study. The variation of Ca2+ and PO43− ions versus time in simulated body fluid (SBF) solution were measured by inductively coupled plasma (ICP) analysis during 1 month and the results showed that the mineralization of calcium phosphate (Ca‐P) on HA coated porous samples was much more than that in non‐coated sample. The SEM micrographs and energy‐dispersive X‐ray spectroscopy (EDS or EDX) analysis of the samples after 1 month of immersing in SBF confirm that Ca‐P phase (bone‐like apatite) was significantly mineralized on HA coated porous BT samples. It was concluded that the nanostructured HA coating would improve the bioactivity of BT foam.