Cytompatibility assessment of the surface of titanium after phosphorylation.

In this study, orthophosphoric acid (H3PO4) in the treatment of porous titanium (Ti) is investigated and the ability of rat bone marrow stromal cells (BMSCs) is assessed to proliferate and differentiate on these modified surfaces in vitro. To improve the cytocompatibility of Ti surfaces, pure Ti was activated commercially by simple chemical pretreatment in H3PO4 with different densities. Next, the phosphorylated specimens were soaked in simulated body fluid (SBF) to study the effect of biomineralization. The3-[4,5-dimethylthiazol-2-y1]-2, 5-diphenytetrazolium bromide (MTT) assay and the measurement of alkaline phosphatase (ALP) activity utilized to assess proliferation and differentiation of BMSCs on exposure to modified Ti surfaces. Scanning electron microscopic (SEM) images showed that the surfaces of the pre-treated samples were characterized by a complex structure which consisted of a mesh-like morphological matrix and an uniform surface with different morphic crystals of titanium dihydrogen orthophosphate (Ti(H2PO4)3). These crystals contained hydroxyl with phosphate residues that resulted in biomineralization of cells. Therefore, BMSCs reveales a well-dispersed morphology on these modified and functionalized Ti surfaces. The viability and ALP activity of BMSCs on these altered biomimetic surfaces are found to be greater than those of the controls. It is concluded that the treatment of Ti by acid etching in orthophosphoric acid is a suitable method to enhance the in vitro proliferation and differentiation of BMSCs.

[A study on the effect of biomineralization and phosphorylation performed on the titanium implant surfaces].

OBJECTIVE: To suggest a chemical surface treatment for titanium and to initiate the formation of hydroxycarbonated apatite (HCA) on titanium surface during in vitro bioactivity tests in simulated body fluid (SBF). METHODS: To improve the bone-bonding ability of Ti implants, commercially pure titanium (cpTi) by a simple chemical pre-treatment in orthophosphoric acid (H(3)PO(4)) with different density was activated, and then the phosphorylation specimens were soaked in SBF to investigate the function of biomineralization. RESULTS: The scanning electron microscope (SEM) photographs showed that the surfaces of the pre-treated samples were characterized by a complex construction, which consisted of a mesh-like morphology matrix (a micro-roughened surface) and an uniform surface with different morphous of titanium dihydrogen orthophosphate [Ti(H(2)PO(4))(3)] crystal. After 14 days in SBF a homogeneous biomimetic apatite layer precipitated. CONCLUSIONS: These data suggest that the treatment of titanium by acid etching in orthophosphoric acid is a suitable method to provide the titanium implant with bone-bonding ability.