The Effects Of Nanostructured Titanium Fabricated Via Surface Plastic Deformation On Biological Behaviour Of MC3T3 Cell

【Objective】The morphologies on the surface of medical biomaterials can promote the biocompatibility.Pure titanium is known as the best medical materials in oral implantology. Although it has excellent physical,chemical and mechanical property,its biocompatibility is not very good.Many studies have tried to improve the biocompatibility through surface modified methods for some shortage of its biocompatibility.Nanometered is an important technology to improve the biological activity of titanium surface.The study was to observe the effects of nanostructured surface modified by severe plastic deformation on biological behavior of MC3T3 cells and to supply theoretical and experimental evidence for development and application of novel implant materials.【Materials and Methods】Medical Ti sheets(10×10×1 mm³) were subjected to plastic deformation under the certain conditions for 60 minutes.The nanostructured titanium was examined as experimental group,while the untreated titanium was used as control group. The characteristics of plastic deformation material were evaluated by CLSM.MC3T3 cell line cells were cultured on the different titanium surfaces.The effects of titanium surfaces and nanostructured titanium surfaces on cell adhesion and shape were examined using SEM and fluorescence microscope.Cell cycle was analyzed by Flow Cytometry.Actin cytoskeleton was examined by CLSM.RT-PCR was used to assess the mRNA levels ofβ₁-integrin and OPN genes.ANOVA was performed using SAS6.0 software package.【Results】The stainless steel balls of 8 mm in diameter were used and the vibration frequency was 50 Hz.The severe plastic deformation was conducted at room temperature and in vacuum for 60 minutes on each surface.Plastic deformation for 60 minutes yielded expecting nanostructured titanium surface.The nanostructured titanium surface promoted MC3T3 cell adhesion(P＜0.05).MC3T3 cells had more extensive spreading on nanostructured titanium surfaces than on the surface of control group.All experimental groups had actin filaments aligned along the major axis of the cells.Cell cycle has no obviously changes between the two groups.MC3T3 cells on nanostructured titanium surface had higher level ofβ₁-integrin gene expression than control group(P＜0.05).MC3T3 cells on nanostructured titanium had the same level of OPN gene expression as the control group(P＞0.05).【Conelusions】Severe plastic deformation could yield nanostructured titanium surface which obviously promoted the adhesion and spreading of osteoblast cells.The results suggested that nanostructured titanium surface could enhance biocompatibility of medical pure titanium and plastic deformation may become a novel surface modification method for Ti medical material.