Improvement of osteoblast bioactivity and osteoprotegrin gene expression of titanium surface by anodic oxidation / 中国组织工程研究

ABSTRACT

BACKGROUND:Nanostructure formation on titanium surface by anodic oxidation has good biocompatibility with bone tissue. OBJECTIVE:To observe the surface morphology and crystal ine constitution of nanopores microstructure on titanium surface formed by anodic oxidation and to further observe its influence on the MC3T3-E1 osteoblast cells’ biological behavior and the gene expression of osteoprotegerin. METHODS:Nanopores forming on titanium surface by anodic oxidation was prepared as experimental group and polished titanium as control group (12 samples for each group). Mouse MC3T3-E1 osteoblasts were co-cultured with polished pure titanium plate group and anodic oxidation nanopores group. After 7 days of inoculation, cellmorphology was observed using scanning electron microscopy, MTT method was used for the cellproliferation test and the growth curve was made. Gene expression of osteoprotegerin was also detected. RESULTS AND CONCLUSION:After anodic oxidation, a homogeneous and uniform array of nanopores formed;however it had no significant influence on the crystal ine phase of the titanium sample surfaces. Titanium surface with nanopore structure was more favorable than polished titanium surface for cellattachment and spreading. cells on the anodized surface with nanopores had higher celldensity and bigger metal coverage area. cells on the nanopores surface also exhibited a polygonal shape with many filopodia extending in al directions. MTT method showed that the anodized nanopore surface had higher cellamount than the as-polished titanium, and the former was about 1.4 times of the latter group after 7 days of culture. The gene expression level of osteoprotegerin in the MC3T3-E1 cells cultured on anodized titanium surface with nanopores was significantly higher than that on the as-polished titanium (P<0.01). The anodic oxidation treatment is more advantageous for the osteoblasts adhesion and gene expression of osteoprotegerin, thereby promoting the growth of osteoblasts.