| In recent years, different kinds of medicinal materials after implantation showing some biological inertia and surface infection caused the failure of the implant. Different alloy metal materials required reoperation after implantation, not only increase the patient’s appointment times,but also bring harm to the patients psychological and physiological. With bio-degradable magnesium-based metal material obtained constant depth and extension, the conventional metallic material to enhance biocompatibility and antibacterial rate by surface modification, but its effect is not good. This experiment using Magnesium-based metal material itself biodegradable property, excellent biological activity and its characteristic of inhibiting bacteria survival in the degradation of alkaline micro-environment to study a biological functional materials. obtain biological silver coating for ease of magnesium based materials degradation too fast and pre-implant infection problem. And on its surface by micro-arc oxidation coating added silver ions to prepare new biological coating for ease of degradation of magnesiumbased materials too fast and pre-implantation antibacterial effect.Objective: Experiments prepared pure magnesium biological micro-arc oxidation coating by ultrasound micro-arc oxidation technology, and were loaded with different concentrations of silver nitrate and studied the antibacterial properties of biological silver coating on Escherichia coli and Staphylococcus aureus for the promotion of magnesium matrix implant providing a powerful theoretical basis.Methods: Pure magnesium through ultrasound micro-arc oxidation, and adding different concentration of silver nitrate in the electrolyte, prepared silver of pure magnesium micro-arc oxidation coating. Group A for adding silver nitrate 0.00 g/L as the control group, group B for adding silver nitrate concentration is 0.03 g/L, C group for adding silver nitrate concentration is 0.05 g/L, group D for adding silver nitrate concentration of 0.08 g/L. Choosing staphylococcus aureus and escherichia coli as experimental strains, using automatic tablet colony counting method to count antibacterial properties of different silver concentration of pure magnesium micro-arc oxidation coating.Results: Three groups of different concentration of silver coating have different degree of antimicrobial properties, group B was no antibacterial rate on staphylococcus aureus, but its antibacterial rate was greater than 90% on e. coli;group C for e. coli and staphylococcus aureus antibacterial rate were greater than 99%, it showed group C has stable strong antibacterial effect; group D on staphylococcus aureus and escherichia coli antibacterial rates were greater than 99%, it showed group D also has stable strong antibacterial function, adding the blank of poor antibacterial of micro-arc magnesia based materials before degradation after implant. Observing ion dissolution experiment results under electron microscope found when specimens after immersion in simulated body fluids for 24 hours, the silver ion precipitated from surface. And in the precipitation experiments analysis, choosing 0.05 g AgNO3 coating layer analysis, 1d, 3d, 7d, 14 d precipitation concentration of silver ions tend to be uniform, observing the 0.00 g, 0.03 g and 0.05 g, 0.08 gAgNO3 biological coating to simulate fluid soak in 7 days after the precipitation density of silver ion, can be found in the coating with the increasing of content of AgNO3, precipitation of silver element concentration increased, when content of AgNO3 reached 0.05 g, precipitation concentration showed maximum value.Conclusion: When the electrolyte AgNO3 dosage 0.03 g / L have an antibacterial effect, AgNO3 added in excess of 0.05 g / L, have strong antibacterial properties on Staphylococcus aureus and Escherichia coli. |
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