Mechanism Investigation On Osteoblast Adhesion Affected By Ti6Al4V Biological Materials Surface Roughness

Ti-6Al-4V alloys have been widely used in orthopedic field as biomaterials. The stability of endoprosthetic implants depends on a stable connection between the implant material surface and the surrounding bone tissue. It asked for having excellent biocompatibility.The biocompatibility of Ti-material for biomedical, not only have close relationship with the physical and chemical surface properties, but also deep with the morphology of surface. In recent years, the morphology of surface is a hot topic in the study.Many studies have confirmed that the surface morphology and roughness have a important impact on the cell biological behavior.However,there is no systematic study on the influence of different surface roughness on cell biological behavior. Therefore, making an in-depth study on the influence of different surface roughness on the osteoblast cell adhesion, proliferation and differentiation not only can optimize the morphology of the Ti-material for biomedical implant but also can provide the theoretical basis for cell adsorption on the Ti-material for biomedical and patterning technology on Ti surface.In this paper, we discussed the adhesion mechanism of cells on surface and the mathematical models of cells adhesion and proliferation affected by roughness. Cells and surface interactions is essential cells and surface-binding protein (or other biological molecules) interactions. Integrin is a major membrane protein that media cells adhesion on substrate.A series of titanium alloy (T-i6Al-4V) samples were prepared by polishing, the roughness and morphology are detected by confocal laser scanning microscopy.The roughness of titanium surface ranges from 0.3μm to 1.8μm, and there are rule grooves on the surface.The MC3T3 mouse osteoblastic cells were thawed and subcultured.Cells were seeded on the titanium implants;cell adhesion and proliferation were carried out using MTT method and cell counting method,respectively.Comparethe adhesion and proliferation on different roughness surface;using SPSS 13.0,the experimental results were analyzed statistically. Analysis of experimental results shows that the roughness in 0.5μm-1.0μm was good in biocompatibility. However, the rougher or smoother surface will affect the biological behavior of osteoblasts. The roughness in 0.9μm-1.0μm was the most uitable for osteoblast adhesion and proliferation.Using scanning electron microscopy, confocal laser scanning microscopy and three dimensional ultra depth of field micrograhps, observe the osteoblast morphology on different roughness titanium chips and different culture time, and compare with the fluorescent microscopy of the control group.We can see, in the initial culture, cells display a spindle and polygonal morphology; filopodia rich and similar perpendicular to the cell body; the trench on titanium surface causes contact guidance for cells. With the increase of culture time cell morphology is more evident, displaying spindle, aggregation and close connection.