Study Of Compatibility For Fluoride Treater Biodegradable AZ31B Magnesium Alloys

ObjectiveMagnesium as a macroelement that can be absorbed by human bodies and with high specific strength and stiffness has a better toughness and processability than non-metals,so that it would not only be able to overcome some shortcomings such as low intensity and stiffness of polymer material near human bone tissue,but also it has rich resources at a very low cost..Current,the degradation of magnesium alloys was quick.It would affect the biological compatibility of magnesium alloys.But the surface fluoride treatment technique could change the surface composition and the degradation rate of the magnesium and magnesium alloys.This experiment took the induced people bone marrow stromal cells as testing cells,to evaluate the biological compatibility of magnesium alloy materials with different surface fluoride treatments,to provide theoretical and experimental data for the design and development of the magnesium and magnesium alloy used as bone implant materials.MethodsUsed density gradient centrifugation way combining with the method of adhereh culture to separate and purificate human bone marrow stromal cells.Passaged and amplificated the cells.Put the mineralization induced liquid into the subcultring cells,which contained DMEM-F12;10mmol/Lβ-Glycerol sodium phosphate;10-8mol/L dexamethasone;50μg/L levorotatory ascorbic acid,15% fetal bovine serum.Used the inverted phase contrast microscope to observe the morphology difference of bone marrow stromal cells before and after the induction,and used the flow cytometric to detect surface markers of bone marrow stromal cells,and used MTT method to test the growth curve of bone marrow stromal cells befoe and after induction,identificated and detected bone marrow stromal cells and their activity after induction with alkaline phosphatase calcium-cobalt dyeing and alizarin bordeaux mineralizatinodular dyeing.AZ31B magnesium alloys was control Group A.AZ31B magnesium alloy materials with different fluoride treatments was divided into Group B,C,and D.The degradation speed of the Group D was the slowest,the Group B was the fastest. Used scanning electron microscope to observe the physical morphology change of material surface of the control Group A,Group B with different fluoride treatment techniques,experimental group C and D.Applied spectrum analysis system to analysis the composition of the material surface chemical elements.The induced people bone marrow stromal cells were the test cells.Used the leaching liquors of the control Group A,Group B with different fluoride treatment techniques,experimental group C and D to test the compatibility in vitro and to evaluate the biological compatibility of different fluoride treatment AZ31B cmagnesium alloy materials.ResultUsed density gradient centrifugation way combining the method of adhereh culture to separate and purificate people bone marrow stromal cells BMSCs.Use the flow cytometric to detect human bone marrow stromal cells CD34,CD45,CD44 and CD105,the positive rate of the cell expression was 99.72%,0.2%,0.93%,98.09%respectively.The mineralizated human bone marrow stromal cells had the feature of the oseobladtic.With the MTT method,this experiment showed that the cell survival rate of AZ31B magnesium alloys with fluorine treatment was significantly higher than AZ31B magnesium alloys without fluoride treatment.The toxicity of cells in the leaching liquor of AZ31B magnesium alloys with fluorine treatment was Grade 1 and was non-toxic to the basic cell growth.The cell survival rate of the experiment group D in AZ31B magnesium alloys with fluorine treatment was the highest.ConclusionThis experiment had proved that the biocompatibility of AZ31B magnesiumalloys with fluoride treatment was superior than AZ31B magnesium alloys without fluorine treatment,and the biocompatibility of AZ31B magnesiumalloys with fluoride treatment in Group D was the best.