Study On Antibacterial Properties And Biocompatibility Of The SLM-fabricated Cu-bearing Titanium Alloy

Objective: Pure titanium and titanium alloys are currently the most widely used alloys for oral implants and surgery.Although they have been strictly aseptically processed and operated before and during surgery,there are still many treatments that cause treatment failure due to postoperative infections;Great progress and the improvement of people’s quality of life also require precise and personalized trends in clinical treatment.In view of this,the systematic basic in vitro experiment of the new titanium alloy(TC4-5Cu)prepared by 3D printing provides a scientific basis for the future research of personalized precision titanium alloy implants.Methods:1.The alloy samples were co-cultured with Staphylococcus aureus for 24 h by plate co-culture method.The antibacterial ability of TC4-5Cu was explored according to the colony formation on the surface of the alloy.2,the alloy and mouse embryonic osteoblast precursor cells(MC3T3-E1)co-culture 1D,3D,7D CCK-8 cell proliferation assay kit to explore the effect of alloy on cell proliferation;alloy and MC3T3-E1 cells The cytoskeleton morphology was observed by rhodamine-ghost pen peptide peptide staining for 4 h,and the alloy was co-cultured with MC3T3-E1 cells for 1D,3D,and the ZEISS field emission scanning electron microscope was used to determine the adhesion of cells on the surface of the alloy.The alloy wa s co-cultured with MC3T3-E1 cells for 72 hours,and apoptosis was determined by FITC/PI flow double staining;finally,the cytotoxicity of TC4-5Cu was systematically explored.3,the alloy and MC3T3-E1 cells co-culture 3D,7D,10 D using ALP / BCA protein assay to explore the early osteogenic ability of the alloy;alloy and MC3T3-E1 cells co-culture 14 D,21D after alizarin red staining exploration alloy Advanced osteogenesis ability;the alloy was co-cultured with MC3T3-E1 cells for 7D.After 10 D,RNA was extracted by reverse transcription and then subjected to qRT-PCR amplification to explore the effect of alloy on the expression of osteogenic related genes in MC3T3-E1 cells.Explore the TC4-5Cu alloy to promote bone formation.Results: 1.Determination of TC4-5Cu-x by plate co-culture method has certain antibacterial ability and antibacterial rate(57.03±1.55)%.2.The value of CCK-8 was used to determine the value-added.The experimental group TC4-5Cu had no significant value-added effect compared with the control group(P>0.05).The phalloidin staining showed that the experimental group had better cell status than the control group;the scanning electron microscope showed the experimental group.There was no obvious difference in surface corrosion observed on the surface of the control group,but the number and state of surface adherent cells were significantly better than those in the control group.The TC4-5Cu in the FITC/PI double staining assay group had the effect of inhibiting apoptosis.P < 0.05).TC4-5Cu alloy promoted early osteogenesis of cells in ALP/BCA assay(P<0.001),among which TC4-5Cu-x performed better;TC4-5Cu alloy promoted advanced cell osteogenesis in alizarin red staining,TC4-5Cu-x performed better;the expression of osteogenic related genes ALP,RUNX2,OPN and COL-I in qRT-PCR increased in cells co-cultured with TC4-5Cu alloy(P<0.05),of which COL-I was in the group.The difference between the time points was not obvious(P>0.05),and the above expression increased TC4-5Cu-x performed better.Conclusions:The Ti-6Al-4V-5Cu alloy prepared by the SLM printing process has excellent in vitro biocompatibility.According to ISO 10993-5,the cytotoxicity level is lower than grade 2,the material is not cytotoxic to cells,and has cells Osteogenesis promotion,in which the fine powder printing sample has better bone-promoting ability than the coarse powder;in addition,it has certain antibacterial ability.