The Experiment Of The Micro-arc Oxidation Film's Biocompatibility With Mesenchymal Stem Cell

Aims:Micro-arc oxidation (MAO) is a newly developed technology to form ceramic coating on the metal surface. Compared to the tradition ceramic coatings, MAO ceramic coating is anti-corrosion and desquamate-resistance. For the layer of MAO coating was integrated with metal surface tightly due to its special forming method. Our experiment is intended to form MAO ceramic coatings under different voltage to explore the MAO ceramic forming condition. The varied MAO surface feature and changing element of ceramic membrane formed under different voltage will be observed by SEM and analyzed by EDX. Rat mensenchymal stem cell (MSC) was cultured in vitro to observe its proliferation and bone formation. The biocompatibility of MAO ceramic coating was evaluated by comparing the MSC proliferation condition on MAO, sand-blasting and smooth treated titanium surface.Methods:1. Forming the ceramic film on titanium surface under 480, 520 and 560 voltage through MAO technique. The surface characteristics of the three groups ceramic membrane were recorded by Scanning Electronic Microscopy (SEM) and was analyzed by Energy Dispersion X ray Fluorescence(EDX).2. Rat mensenchymal stem cell (MSC) was cultured in vitro. The auxodrome of MSC was surveyed and evaluated. Cultured in the bone-inducing culture medium, MSC showed its good property of bone formation.3. We set the 520 voltage MAO treated titanium as the experiment group, sandblasting and smooth treated titanium as controlled groups. MSC was seeded on the titanium surface of three groups at density of 5×104 /ml. On the 1st, 3rd, 5th and 7th day, the numbers of MSC attached on the titanium surface was calculated separately, the morphous of MSC was observed by fluorescence microscope. SEM record the condition of MSC attached on the surface of different treated titanium.Results:1. MAO treated titanium presents a porous surface under the SEM scanning. There are numerous 2-25μm diameter micropores scattered on its surface. The diameter of the micropores and the element contents of the ceramic film are varied along with the changing of voltage. However, there is not any regular relationship between voltage and the surface characteristic.2. The proliferation condition of MSC in vitro was pretty well. Under the bone induce circumstance; MSC presents an upstanding bone formation property. Calcium nodes were formed during two weeks'bone inducing culture.3. MAO treated titanium exhibits an excellent biocompatibility with MSC compared with the other groups. On its rough, porous surface, the proliferation condition of MSC is excelled other groups.Conclusions:1. The characteristic of MAO surface and its elements changed along with the varying voltage. Nevertheless, we can't deduce any relationship between the voltage changing and the MAO surface characteristic. The forming condition including voltage and electrolytic components of MAO still need further study.2. Mesenchymal stem cell possesses a good proliferation ability and bone formation property in vitro.3. Micro-arc oxidation is a good method to form the ceramic surface on implant surface, which has a promising future due to its excellent biocompatibility.