Effect Of The Micro-nano Surface Of Titanium Alloy On Biological Behavior Of Ostecblasts

Commercially pure titanium and titanium alloy is preferred for dentalimplants or prosthesis, due to its excellent excellent biocompatibility, corrosionresistance, durability, strength and good surface properties. In general, only theimplant surface is in direct contact with the host tissue, and thus has a series ofcell-cellular effect, the cell-protein function after contacting the host fluid,forms the stable osseointegration. It is widely accepted that surface propertiescontrol the biological behavior between tissue-implant interfaces. Consequently,several studies have focused their efforts in the search of implant surfacemodification that promotes the biological behavior of osteoblasts on thebiomaterial, promotes the function of osteoblasts. Implant surface topographymainly focused on micro-morphology, It has been shown that rough surfaceshave generally proven superior to smooth surfaces in terms of promotingimplant osseointegration and ultimately increases the removal torques ofimplants. Micro-topography could promote the differentiation of osteoblasts,but inhibited the proliferation of osteoblasts. In recent years, nano-morphologyhas been attentioned, it could provide biomimetic environment for osteoblasts,promote adhesion, proliferation, differentiation, matrix synthesis of osteoblast,scholars began to study the biomaterials of hierarchical micro-nano surface.However, hierarchical micro-nano topography surface of the specific role is notclear, its application and clinical is challenge.To further understand the hierarchical micro-nano surface how it affects thebiological activity of osteoblast. In this study, the hierarchical micro-nano surfacetopographies were produced on titanium alloy by Electrochemical (EC) methods.The MG-63 cells were cultured respectively on EC, SLA, and M surface,counting the number of living cells under a microscope 1 -24 h; On 1 d, 3 d, 5 d and 7 d, using MTT method to evaluate the cell proliferation rate and the cellmorphology and structure was observed by FSEM after vaccination 1 d, 3 d, 5 d,7d; and alkaline phosphatase detection kit was used to detect the change of activityof alkaline phosphatase on 1 d, 3 d, 5 d , 7d.The results showed that MG-63 cells were inoculated after the surface 1-24 h,adherence rate increased with time, cells were inoculated 1h adherence rate of ECwas significantly higher than M and SLA group, in which adherence rate of Mgroup is the lowest(P < 0.05). With the extension of time, MG-63 cells culturedon EC, SLA, and M the surface were all proliferated,MG-63 cell proliferation inEC group was significantly higher than SLA group in 3d, 7d and was significantlyhigher than M group in 5d, 7d, and cell proliferation capacity in M group was thelowest among the three(P < 0.05). The proliferation of M group is inhibited at 1d, and at 5 d and 7 d continues to increase. FSEM showed that: the first 1d,MG-63 cell attached on the bowl-shaped concave of EC surface, showingpolygonal, cell body stretched out a number of pseudopodium and microvilli;MG-63 cells attached on SLA surface were mainly spindle-shaped and fewspherical, pseudopodium and microvillus were less, shape and stretch of cells isnot as good as EC; MG-63 cells on M surface were mainly spherical, fewspindle-shaped, close to the surface, mainly in microvilli adhesion, pseudo podwas rare; On 3d, EC surface were fully covered with the MG-63 cells,bowl-shaped concave and other forms were covered by cells. The cells closelyattached to the EC titanium surface and became more flat; SLA surfacemicro-morphology was covered by MG-63 cells, which were spherical,spindle-shaped and irregular shaped. The cells connected to each other and had noobvious protrusions; MG-63 cells on M surface were spherical and not firmlyattached to surface. They showed mainly microvilli but rare pseudopodia; on 5 dand 7d, cells closed to the EC surface was more flat and a few cells showedspherical.MG-63 cells on SLA surface is flat shape and there were a small number of spindle-shaped and spherical cells. Which with microvilli protruding andconnecting to each other, closely stickled onto the surface; the cells on M surfaceof were still spherical, but had already stretched, the cells extended microvilli,which already connected, closely attached to the surface and there were rarepseudopodia. ALP activity of EC, SLA and the M group on 1 d, 3 d, 5 d and 7dwere time-dependent increasing, EC group was significantly higher than the othergroups (P <0.05), in which the highest was EC group, and M group was the lowest;ALP activity of SLA and the M group was significantly lower than normal group(P <0.05).In a word, the hierarchical micro-nano surface topographies were producedon titanium alloy by electrochemical methods. This surface has favorablebiocompatibility, which can promote osteoblast adhesion, proliferation anddifferentiation. Which can provides a theoretical basis to study the interactionbetween implant and osteoblast, and further coordination of optimizing the role ofmicromorphology and nanotopography.