Biocompatibility Of Pure Magnesium Implants Coated With Human Lactoferrin By Ultrasonic Microarc Oxidation

Objective: Ultrasound micro-arc oxidation(UMAO)on pure magnesium surface and silane-coupled human lactoferrin(HLF)were used to form a composite membrane of UMAOsilane-HLF in order to improve the early osseointegration ability of medical Mg in animals and to regulate its degradation rate.Methods: Ultrasound micro-arc oxidation of pure magnesium(UMAO)was used as control group A,UMAO-silane as experimental group B,and UMAO-silane-0.1 g/L human lactoferrin as experimental group C.The surface morphology of the three groups of pure magnesium nails with different membranes was observed by scanning electron microscopy.Scanning electron microscopy was used to observe the surface morphology of the three groups of pure magnesium nails with different membrane.Three groups of magnesium bone nails were implanted into the unilateral mandible of rabbits.Immunofluorescent markers were injected into the mandible within a specified time.Rabbits were sacrificed in stages after 2,4 and 8 weeks.Then cut off the nailed mandible.Bone bonding and surface absorption of implant nails were observed by oral digital cone beam CT(CBCT),Bone mineralization deposition was observed by confocal laser scanning electron microscopy,and new bone and energy were observed by scanning electron microscopy.The element distribution at the interface was observed by spectral analysis.Results: Scanning electron microscopy(SEM)showed that after treatment with UMAO-silane-human lactoferrin composite film,the surface pore of pure magnesium nails gradually reduced and sealed,and there were N and Fe elements on the metal surface.Bone necrosis and defect did not occur at the implantbone interface,and soft tissue healed well.The low density shadow around the implant was the smallest in the human lactoferrin group at the 8th week of CBCT observation.The ability of attaching new bone tissue to the implant nail surface and the ability of anti-degradation were all group C > group B > group A.Scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)showed that after 8 weeks of treatment with UMAO-silane-human lactoferrin composite membrane,the bone nails in group C were most closely bound to the bone interface,and new bone bands were formed between the implant and bone tissue.A large number of Ca and P elements were found in this area than those in group B and group A.Laser confocal microscopy showed that the fluorescence bands around the magnesium bone with human lactoferrin composite film in group C were the most continuous,showing the highest brightness and the widest spacing.SPSS 17.0 statistical analysis showed that the mineralization deposition rate of the new bone in group C was significantly higher than that in group C and UMAO after implantation for 2,4 and 8 weeks,which has statistical significance.Conclusion: After the pure magnesium nails were coupled with human lactoferrin by ultrasonic microarc oxidation silane,the coating material achieved pore sealing,slowed down the degradation rate in animals,had good biocompatibility,and promoted bone bonding and early bone growth.