Synthesis And Characterizations Of A Novelbone Cement Based On Magnesium-containing PMMA Microspheres

Objective: The objective of this study is to synthesize a novelbone cement based on magnesium-containing PMMA microspheres,and then test its characteristics of material properties,biosafety and histocompatibility.Methods: The magnesium microspheres were added to PMMA by different proportion(33%,50%,67%)to fabricate a novel Mg-PMMA composite bone cement with biodegradability.Culturing MC3T3-E1 cells in the leach liquor of Mg-PMMA and using Cell Counting Kit-8(CCK-8)to test cell proliferation at day 1,3,5 and 7.The Mg-PMMA cylinders were implanted into the femoral condyle of New Zealand rabbits.After 10 weeks,materials were drawn to test their histocompatibility by Micro-CT test and push-out test.The alkaline phosphatase(ALP)activity was tested using ALP activity kit and alizarin red stainingwas carried out successively.Results:Results of mechanical tests showed that the compressive strength and bending strength were not significantly affected by the addition of Mg to PMMA.Micro-CT suggested that the novel bone cement was partially degraded and bone formation was observed.Push-out test indicated abetter-linked interface of Mg-PMMA between material and bone tissue than that of pure PMMA.CCK-8 assay showed that the proliferation of MC3T3-E1 cells was proportional to the proportion of Mg and was significantly better than that of pure PMMA and control group.Results of ALP activity and alizarin red stainingshowed that the magnesium added could enhance osteogenesis of bone cement material.Conclusion: In this research,a novel bone cement material of Mg-PMMA was synthesized.The mechanical tests showed that the addition of Mg had no significant effect on compressive strength and bending strength of the bone cement,but increased the biological safety,biocompatibility and osteogenetic ability.With the degradation of Mg,an interconnected porous structure was formed inside Mg-PMMA,which was beneficial to the growth of bone tissue.The novel Mg-PMMA material could effectively improve the characteristics of traditional PMMA,which shows a great promise in clinical application.