The Preparation And Biocompatibility Research Of Micro-Groove Surface Of Several Inorganic Materials

It is difficult for a single material to satisfy the requirements of biomedical appliance with both functionality and biocompatibility.Therefore surface modification of biomaterials has become an important issue for researchers.Surface-patterning, which can influence the cell behavior such as cell distribution, proliferation and locomotion,has become an important approach to the surface modification of biomaterials.In this paper,a series micro-groove patterns surface,such as Si-Si,SiO₂-SiO₂, SiO₂-Si,TiO₂-TiO₂,TiO₂-SiO₂ and Si-N-O were fabricated by photolithograhy,wet etching technique,unbanlanced magnetron sputtering technique and spin-off technology.The scanning electron microscope(SEM),optical microscope and surface profiler were adopted to observe the surface topography.The element distribution of patterned surface was evaluated by energy dispersive X-ray detector (EDX).The microstructure of the TiO₂ flim was analyzed by X-ray diffraction (XRD);the chemical composition and structure of Si-N-O film were characterized by X-ray photoelectron spectroscopy(XPS),and the wettability of the samples was estimated by the contact angle goniometer.The hemocompatibility and tissue compatibility with cell were evaluated by the platelet adhesion and the endothelial cells culture tests.The result showed that the micropatterns prepared by those technologies above were well organized stripe-like microgrooves.The size of Si-Si pattern,SiO₂-SiO₂ pattern,SiO₂-Si pattern,TiO₂-TiO₂ pattern and TiO₂-SiO₂ pattern was 15μm,the depth range of groove was 0.4±0.1μm.The patterns with the same material had the uniform chemical composition,and the composition of interval patterns had significant differences in grooves and ridges.The TiO₂ film had the anatase structure mixed with a little rutile structure.The sizes of Si-N-O patterns were 20μm,30μm, 40μm,the depth of groove was 2μm and 4μm,respectively.The Si-N-O film deposited at 5sccm was composed inorganic Si,Si₃N₄ and SiO_x(x≤2),while the film deposited at 20sccm was composed Si₃N₄ and SiO_x(x≤2).The contact angles of the Si and SiO₂ pattern samples were smaller than that of their flat samples.However,the contact angle of TiO₂-TiO₂ pattern sample was bigger than that of its flat sample.The interval patterns were not observed regularity of contact angle.The contact angles on the micro-patterned surfaces of Si-N-O films increased when N₂ flow changed from 5sccm to 20sccm(whatever for flat or patterned samples),and the contact angles of flat samples were bigger than those of patterned samples for both deposition processes.The platelet adhesion results presented that the TiO₂-SiO₂ pattern had better blood compatibility than Si-Si,SiO₂-SiO₂,SiO₂-Si,TiO₂-TiO₂ pattens and there was no significant difference between the samples of the the micro-patterned surfaces of Si-N-O films.The result of endothelial cells culture showed that the TiO₂ samples had the better ability of enhanced adhesion of cells than the Si and SiO₂ samples.For Si-N-O samples,the patterned surface can promote the proliferation and viability of endothelial cells.The quantity of cells on the samples deposited at 5sccm were higger than that of the samples deposited at 20 sccm whatever for flat or patterned samples.The quantitative morphology analysis of the endothlial cell on microgrooved surface of Si-N-O films showed that the shape of cell was limited by the micropattern obviously and most of cells were guided to grow parallel to the direction of aligned microgroove.