A New Study On Biocompatibility And Antibacterial Activity Of Mg Alloys Through Alloying For Orthopedic

Objective:Objective:to compare the antibacterial ability,corrosion resistance and biocompatibility of Mg-0.1Ga/Mg-0.1Sr/Mg-0.1Ga-0.1Sr alloy/Mg/Ti in SD rats in vitro and in vivo.Exploring the feasibility of Mg-0.1Ga-0.1Sr alloy as a new plant in human body.Methods:In vitro experiments:1.Corrosion resistance of groups of materials cultured in TSB medium.2.Cytotoxicity Evaluation of groups of materials on(hBMSCs)Culture of Human Bone Marrow Mesenchymal Stem cells in Vitro.3.1.groups of materials was cultured in culture medium with Escherichia coli,Staphylococcus aureus and Staphylococcus epidermidis to judge antibacterial ability.In vivo experiments:32 Sprague Dawley(SD)mice were used in vivo.Osteomyelitis model was established with Staphylococcus aureus(ATCC 43300).The rats were randomly divided into 7 groups.Randomly divided into 7 groups of open hole modeling,the double-layer cortex was drilled through,the prepared sample was inserted into the large medullary cavity,and the bone wax was closed.Sterile saline is then washed,sutured layer by layer.1.According to histopathology,2 femurs in each group were fixed in 10%neutral buffer solution,and coronal sections were used to evaluate bone regeneration with Massons trichrome staining.2.The surface morphology of magnesium alloy rod recovered from femur was observed by scanning electron microscope(SEM).Results:1.PH,mass loss and ion concentration:The Mg concentration of Mg-0.1Sr and Mg-0.1Ga-0.1Sr samples was lower than that of pure Mg samples at each time point.2.Cytotoxicity test:In blank group,hBMSCs had good cell expansibility,titanium sample had a small number of dead cells,magnesium alloy containing Ga had less toxicity to hBMSCs,and the proportion of surviving cells was higher than that of Mg without Ga.3.In vitro antimicrobial test:All magnesium alloys in this study have good antibacterial activity,which is caused by the release of Ga3 from magnesium alloys containing Ga through their biodegradation properties.4.In vitro examination:The presence of bacteria on the surface of rod-like implants removed from rats was quantitatively analyzed by diffusion plate method.group 5>group 1>group 2?group 4>group 3.A large number of fibrous tissues were produced near pure Mg,Mg-0.1Ga,Mg-0.1Sr and Mg-0.1Ga-0.1Sr alloys,and a large number of red mature bone tissues were found around titanium and blank groups.The damage degree of implants was found in the order of Mg>Mg-0.1Ga>Mg-0.1Sr>Mg-0.1Ga-0.1Sr.Conclusion:All the Mg alloys in this study have good antibacterial activity.Mg alloy implants degrade and release the ions of Mg~2 and biocompatible alloy ions(such as Zn~2,Ca~2,etc.).As a result of promoting the biological activity of the surrounding bone cells and promoting the formation of new bone tissue in the vicinity of the Mg implant,all of the Mg implants exhibit a strong toxicity to the Staphylococcus aureus,Ga and Sr are unique to their significant bactericidal activity,.