Study On The Coating Of Magnetic Hydroxyapatite On Titanium Surface By Electrodeposition

As one of the common biomaterials, titanium was widely used in clinicalorthopedics, due to its excellent mechanical property and biocompatibility. However,titanium is generally lack of bioactivity. Once implantation, it only passively integrateswith surrounding bone tissue, being lack of oseeointegration. Thus, these disadvantageslimited its application in the field of implant technology.Hydroxyapatite (HA) is the major inorganic constituents of human bone and teethwith good bioactivity and biocompatibility, which was widely applied in the biomedicalfiled, such as the filling and the repair material of bone injury. Previouse studiesdemonstrated that although normal hydroxyapatite had good biocompatibility, it couldnot stimulate progenitor cells to differentiate into osteoblasts. On the other hand,although the magnetic field could stimulate progenitor cells to differentiate intoosteoblasts, it could not fill the space of long bone injury. The thesis is thus focused onthe synthesis of magnetic hydroxyapatite by the combination of the advantage of thosecomponents. The synthesized magnetic hydroxyapatite had good biocompatibility as thehydroxyapatite, while stimulating the differentiation of progenitor cells.In this thesis, hydroxyapatite and magnetic hydroxyapatite were deposited on thesurface of titanium through electrodeposition,. The modified titanium has theadvantages of the titanium with good mechanical property and the magnetichydroxyapatite with good biocompatibility and bone induction property.The main content of the study includes:①Preparation and characterizations of hydroxyapatite and magnetic hydroxyapatite.Hydroxyapatite and magnetic hydroxyapatite were prepared separately byco-precipitation method. Furthermore, the physical properties of the materials werecharacterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD), simulation method, hysteresis loop, respectively;②Surface treatment and characterization of titanium. The coatings of hydroxyapatiteand magnetic hydroxyapatite on the titanium surface were produced by the methodof electrodeposition, then the modified titanium were characterized by scanningelectron microscopy (SEM),FTIR, and XRD;③Primary culture and identification of neonatal SD rat derived osteoblasts: Theosteoblasts were isolated from the calvaria of neonatal SD, which were purified by differential adhesion method and further identified by the morphology observation,alizarin red staining, and alkaline phosphatase staining.④Biological evaluation of modified titanium: the osteoblasts were seeded onto themodified titanium surface for4days. The proliferation of the osteoblasts wasmeasured by MTT assay. Meanwhile the ALP activity was evaluated to reveal theirdifferentiation.We achieved results as follows: the hydroxyapatite and magnetic hydroxyapatitewere successfully synthesized by co-precipitation method. The coatings ofhydroxyapatite and magnetic hydroxyapatite were produced onto titanium surface bythe method of electrodeposition. Cell biology assay confirmed that the modifiedtitanium was beneficial for the growth of osteoblasts.