The Surface Organic Modification And Biocompatibility Of Magnesium-based Materials

Biomedical materials is closely related to people’s health and the quality of life, which plays an important role in the biomedical field.Magnesium as a biological material having suitable mechanical properties and good biocompatibility, but the corrosion rate is too fast, limiting its development in the field of biomedical materials. In order to improve corrosion resistance and biological activity of magnesium, in this paper, Phytic acid(PA), organic composite film(OCF) and phytic acid-APTES macromolecules(PAS) compound were selected to modify the pure magnesium, optimizing the process parameters of film formation,meanwhile the corrosion behavior of the samples and its biocompatibility was studied. This paper has made the following conclusions:(1)The surface treatment process of PA, OCF and PAS has been optimized through orthogonal test, respectively. the optimum film forming conditions are:1)PA: solution’s pH:6, solution’s concentration:7g/L, the deposition time:30min, the film formation temperature:50℃.2)OCF: solution’s pH:10, APTES volume fraction:1%, the deposition time:30s, the curing temperature:100 ℃;3)PAS: Mass ratio of phytic acid and APTES:1, the deposition time:10min, the film formation temperature:60℃.(2)SBF solution immersion and electrochemical experiments show that OCF presents more significant effect to enhancing the corrosion resistance of pure magnesium among the three process. After soaking in the SBF solution 30 d, samples integrity preserved and sample’s surface flatness is higher. OCF modified pure magnesium sample’s corrosion current density by 12.820×10-4mA/mm2 reduced to 0.48×10-4mA/mm2.(3)The EDS analysis results indicates that the surface of organic composite film modified pure magnesium samples Ca and P increases faster than the untreated samples during immersion, showing superior bioactivity.(5) The hemolysis rate of PA, OCF and PAS modified pure magnesium are respectively 4.3%, 3.2% and 3.7%, which are within the demand(<5%), and the hemolysis rate of OCF is the lowest.(5) The leaching solution of untreated and modified magnesium shows the HUVECs toxicity of level 1 after 1d, 3d and 5d. The test results presents that the leaching solution of samples can meet the demand of cytoxicity.