The Study Of Construction Of 3D Printing Beta-TCP Loaded INH/RFP PLGA Anti Tuberculosis Sustained Release Microspheres And Its Anti INH Ection And Osteogenic Action

Objective: Construction of 3D printing-TCP scaffolds loaded INH/RFP PLGA microspheres;Study on cytotoxicity and osteogenesis of 3D printed ?-TCP-INH/RFP-PLGA composite;The model of chronic osteomyelitis was constructed and the composite was implanted into the model to observe the therapeutic effect of the material.;The purpose of this study is to invent a new bone repair material for the treatment of INHectious bone defects,and to provide a new idea and a new plan for clinical treatment.Method: 1.Construction of 3D printing-TCP scaffolds loaded INH/RFP PLGA microspheres;The CAD software was designed and the 3D printer was used to print beta-TCP stents,and at last 1200 C was calcined at high temperature.The preparation process of INH/RFP PLGA microspheres prepared by the emulsification solvent evaporation method was optimized by orthogonal design.The related characterization and the sustained release properties of microspheres were measured.Finally,the centrifugal shock method was used to combine the 3D printed beta-TCP with INH/RFP PLGA sustained-release microspheres to determine the corresponding antibacterial ability.2.Study on cytotoxicity and osteogenesis of 3D printed ?-TCP-INH/RFP-PLGA composite The experiment was divided into 4 groups: blank control group,simple scaffold group,microsphere group and composite material group;The material was co cultured with rat bone marrow mesenchymal stem cel s(BMSCs)to study the toxicity and osteogenesis of the materials.3.The model of chronic osteomyelitis was constructed and the composite was implanted into the model to observe the therapeutic effect of the material.Using 2mm's K irschner's needle to drill the 2cm on the rabbit's femur condyle,and injection of MRSA bacteria with different concentrations,Study of the relationship between bacterial concentration and osteomyelitis model.To explore the rabbit femoral osteomyelitis model constructed by a suitable concentration of MRSA bacteria.4.3D print beta-TCP stent loading INH/RFP PLGA sustained-release microspheres composite materials for the treatment of INHectious bone defects The experimental debridement was divided into 4 groups,the blank group,the microsphere group,the scaffold group and the composite group were implanted into the INHection model respectively.Through the study of INHluence and pathology,the therapeutic effect of materials on INHectious bone defect is studied,which provides a theoretical basis for clinical treatment.Result: 1.Construction of 3D printing-TCP scaffolds loaded INH/RFP PLGA microspheres;Through scanning electron microscope,it is found that the pore of 3D print beta-TCP scaffold is 400 um,and the porosity is(66.34±2.76)%.The compressive strength of the material was 123.5±15.8 N and 7.8±1.2MPa,which accords with the compression strength of human cancellous bone(2-12 Mpa).The PLGA sustained-release microspheres were prepared by emulsion solvent evaporation method.The best preparation process was PLGA concentration 15%,PVA concentration 2%,oil to water ratio 2:1,drug carrier ratio 1:2,rifampicin and isoniazid 3:4 compared with 3:4 by orthogonal test.The average diameter o f the three batches of microspheres was 264±7.0um.The drug loading rates of rifampicin and isoniazid were 14.6±0.7% and 12.6± 0.8%,respectively.The entrapment efficiency of rifampicin and isoniazid was 80.6±1.1% and 52.4±1.2%,respectively.2.Study on cytotoxicity and osteogenesis of 3D printed ?-TCP-INH/RFP-PLGA composite Through CCK8 experiments,the biotoxicity of scaffolds,microspheres and composite materials is low.Alkaline phosphatase and PCR experimental study confirmed the osteogenic effect o f beta-TCP scaffold.The composite has good antibacterial effect.3.The model of chronic osteomyelitis was constructed and the composite was implanted into the model to observe the therapeutic effect of the material.Through screening experiments with different concentrations of MRSA bacteria,it is concluded that the best concentration of rabbit chronic osteomyelitis model is 1×106CFU~1×107CFU.This experiment is simple and feasible,and is the best concentration for rabbit chronic femoral osteomyelitis model.4.3D print beta-TCP stent loading INH/RFP PLGA sustained-release microspheres composite materials for the treatment of INHectious bone defects Through the experimental study on the implantation of osteomyelitis model of composite materials,the microsphere group has good antibacterial properties,composite materials not only have good antibacterial properties,can promote bone ingrowth;composite materials can become a new type of antibacterial material and bone repair period.5.Statistical method The data were analyzed by one-way ANOVA and orthogonal test.The LSD method was used to compare the groups.Conclusion 3D printing-TCP scaffolds loaded INH/RFP PLGA microspheres composite material has good biological performance in the treatment of chronic osteomyelitis,has a strong role in antibacterial and bone repair in the treatment of chronic osteomyelitis;the future individual scheme provides new idea and solution,is an ideal bone repair material.