Study On Porous Complex Loaded With RFP As Repair Material For Tuberculosis Bone Defect

Objective:RFP(RIFAMPICIN/Rifampin,RIFAMPICIN)as the main Drug,using PDLLA(Poly real-DL Lactic Acid racemic polytechnic Acid),nHA(nano-hydroxyapatite nanometer hydroxyapatite)as a DDS(Drug Delivery System,Drug Delivery System)carrier materials,to explore the feasibility of the composite materials to repair,but also in the biological safety of porous composite,biodegradability,bone induced properties,such as,medicine slow release and anti-tb activity in vitro and value analysis.Methods:(1)Porous RFP/PDLLA/nHA composites were prepared,the drug loading,entrapment efficiency,porosity and molding were observed,and the characterization of the synthesized products was observed and analyzed by environmental scanning electron microscope(XRD)and XRD(X-ray diffraction X),FTIR(Fourier transform infrared spectroscope,Fourier transform infrared spectroscopy).(2)Using PBS(phosphate buffered saline),phosphate buffer solution as the release medium,the degradation properties in vitro,in vivo and drug release properties of RFP/PDLLA/nHA composites were observed and analyzed.(3)PDLLA/nHA composite was used as a reference,and the growth and proliferation of MC3T3-E1 cells were observed after co-culture with the pre-osteoblast MC3T3-E1 in the composite,and then the cytotoxicity of the porous RFP/PDLLA/nHA complex was analyzed and the tissue compatibility of the composite was evaluated.(4)After 4 weeks of induction and differentiation of RFP/PDLLA/NHA complex and mouse MC3T3-E1 cells,ALP(alkaline phosphatase)content,OCN(osteocalcin,osteocalcin)and CoL-I(COLLAGEN-I,type ? collagen)expression level of MC3T3-E1 cells were measured respectively,so as to evaluate the osteoinduction performance of the composite in vitro.(5)"O" on the gold amine dyeing,acid dyeing,fluorescent MicroMGITTM interpreter bacteria and the FDA detection results of observation and analysis,and evaluation of composite materials in vitro anti-tb performance.Results:(1)Composite raw material of RFP/PDLLA/nHA prepared in the study was prepared by solvent evaporation,and the composite was orange,and was a loose and porous sponge.The Fourier transform infrared spectrum analysis demonstrated the existence of the PDLLA and the RFP,and there was no new image and new cross-linking and coupling,and no new impurities were introduced.(2)There are two rapid growth periods in the process of weight loss rate and pH value of porous RFP/PDLLA/nHA composites.The composites show uneven surface after degradation in vivo,there is a certain degree of fiber membrane coverage,and the combination with tissue is more extensive in vivo.After 12 weeks of degradation in vivo,the degradation rate of the composites was significantly greater than that in vitro.(3)The co-culture of composite and MC3T3-E1 cells showed that the cells grew well,a large number of cells proliferated and the nucleus was intact,the pore structure collapsed in the composites,and the cells had good safety and adaptability,and there was no significant cytotoxicity,and there was no significant inhibitory effect on cell proliferation.The operation of the mice in the group was completed successfully,the anesthesia recovered after operation,and the incision healed well.(4)The activity of ALP in RFP/PDLLA/nHA group increased with the increase of induction culture time.Porous RFP/PDLLA/nHA composites had the advantage of promoting the maturation and differentiation of MC3T3-E1 cells and could play a significant role in repairing bone defects.(5)The RFP/PDLLA/nHA material was orange-yellow for 8 weeks,with clear and light-transmitting color,no obvious colony forming and aggregation of Mycobacterium tuberculosis,and negative acid-fast staining;and the tuberculosis in the RFP/PDLLA/nHA material group can be killed by the RFP released by the composite material.The results of flow cytometry show that the existence of viable Mycobacterium tuberculosis can not be detected in the material.Conclusion:The porous PDLLA/nHA composite of RFP has outstanding performance in all respects,and can be used as a repair material for tuberculous bone defect.However,the effect and mechanism of the composite material are still to be studied and analyzed.