Preparation Of Microporous Titanium Fabricated By Selective Laser Melting Technology And The Evaluation Of Its Bioactivity In Vitro

Objective In this study,titanium specimens were taken as the experimental objects,preparation of the microporous titanium produced by selective laser melting technology,then take the bioactive treatment on microporous titanium.By contrasting with the other four different titanium surfaces,investigate whether the microporous titanium has an advantage biological activity in vitro.Material and methods PT:10 x 10 x 2mm titanium(n=150),titanium surface was polished with the carborundum(800#to7000#),and then followed by ultrasonic cleaning machine.SLA:A total of 30 smooth titanium samples were randomly selected,sandblasted on the surface of titanium specimens,washed with water in an ultrasonic cleaner,dried and then placed in a mixture of 18% hydrochloric acid and 49% sulfuric acid,cleaning and drying standby.Mod SLA:Mod SLA is the same as the SLA treatment but is carried out under nitrogen protection and is stored in isotonic sodium chloride solution before use to prevent exposure to air.SLM:A total of 60 smooth titanium samples were randomly selected from smooth titanium specimens,EOSINT M270 SLM machine prepared SLM microporous titanium with titanium particles.Wash with water in an ultrasonic cleaner,drying.SLM-T: 30 titanium samples were randomly selected from the SLM specimens,and then placed in 5mol/L Na OH,60°C for 24 h,moreover,placed in 0.5 mmol/L HCL,40°C for 24 h,distilled water cleaning,drying.Heat to 600 °C for 1h and cool at room temperature,SLM-T wasrecorded as experimental group,the blank control group was PT and the negative control group was SLA,Mod SLA and SLM.Field emission scanning electron microscopy(FESEM)was utilized to detect the surface physicochemical properties and to measure the pore size of the experimental group.The human serum albumin ELISA kit was used to detect the protein adsorption capacity of the specimen.CCK-8 kit was carries out for detecting proliferation,and alkaline phosphatase(AKP)kit was applied for a kind of indirect determination method for cell differentiation of BMSCs.Results Smooth and shallow scratchescan be seen by sanding the surface by the SEM;SLA and Mod SLA had the similar surface structure;SLA and Mod SLA have the similar surface structure: peak ridge and sharp interlaced;The surface of SLM is very rough,and it can be observed that melting or melting titanium particles;the surface morphology of SLM is similar to that of SLM-T.To 5,10,20,40 and 60 min,the absorbance values between the five groups was statistically significant difference(P(27)0.05).At the same initial concentration of HSA,at any point,the adsorption amount of the smooth group is the least,SLA and Mod SLA,SLM group had more adsorption,the adsorption capacity of SLM-T group was the highest.The proliferative activity of PT,SLA,Mod SLA,SLM and SLM-T was increased.In 3,5 days,the proliferative activity of SLM group and SLM-T group increased significantly(P(27)0.05).The activity of alkaline phosphatase in PT group,SLA group,Mod SLA group,SLM group and SLM-T group increased with time.In 7 days,compared with PT group,SLM group had a significant difference between the activity of alkaline phosphatase(P(27)0.05).In 14 days,SLM-T group and the other 4 groups in the activity of alkaline phosphatase,the difference was statistically significant(P(27)0.05).Conclusion The results of protein adsorption experiments showed the selective laser melting(SLM)microporous titanium had the best adsorption properties after alkali heat treatment and showed excellent biocompatibility in osteoblast proliferation and differentiation.