A New Type Of Magnetic Bone Cement Was Prepared And It’s Effect On Treatment Of Bone Tumors Was Evaluated

Objective :A new m agne tic bone cement was prepared to test it’s com pressive strengths,setting ti me,magneti c characterizations and heat-gene rating abilities.The the effect of kill ing tumor cel ls in alterna ting magnet ic fields in vivo and i n in vi tro were also evaluat ed.In the meantime,the biotoxicity of magnetic bone cement was tested.Method:1.High-temperature organic phase decompositi on was used to prepared the magnet ic nanoparticles t o escribe the characterizat ion,test its composi tion,magnetic properties and heat-ge nerating abili ties.2.In view of the heat-ge nerat ing abil ities,the best magnetic nanoparticles were choosed to prepa re four typ es of magnet ic cement dependent on different proportions of magnetic nanopart icl es(0wt%,5wt %,10wt% and 15wt%).In addi tion,compressive strengt h and set ting time were measured acc ording to the ISO 5833 standard.3.The magnetic bone cement,which is accor d with the clinical m echanic standard ISO 5833,was sel ecte d to measure heat-generating abilities in 390 KHz,22KA/m alternating magne tic field.At the s ame tim e,the apoptosis of MG-63 and proliferation of human osteosarc oma cells(MG-63)were eval uate d.In addition,CCK-8 method was used to t est the cyt otoxicity of mouse fibroblasts(M EF).4.The VX-2 rabbit bone tum or model was constructed.the survival time and the max imum diamet er of the tumor was recorded to evaluate the therape uti c effect of bone tumor in vivo with m agnetic bone cement in t he al ternat ing magnetic fiel d.At the sam e time,the safety of magnetic bone cement was evaluated by blood biochem ical detection method.Results:1.The composition of the prepared C oxFe1-xO4 magnetic nanopar ticles was determined to be C o0.04Fe2.96O4.The obtai ned Co0.04Fe2.96O4 is superpara magnetic,ofwhich 22 nm magnetic nanoparticles have the hi ghe st saturation magnetization(78.06emu/g)and the more excellent heating efficiency.2.Wit h the inc rea se of the co ntent of Co0.0 4Fe2.96 O 4 m agne tic nano particles at 22 nm,the setting time of magnetic bone cem ent i s prolonged.Only the com pressive st rength of magnet ic cement with 5% Co0.04Fe2.96O4 magnetic nanoparticles is(77.1 ± 6.3)MPa which meets t he require ment s of ISO5833.3.magnetic bone cement cont aini ng 5% Co0.04Fe2.96O4 m agnetic nanopart icl es placed in the alternating magne ti c field(390 KHz,21KA/m)for 3m in,tempera ture can reac h 50 ℃ which can meet s the requirement of treatments while heating for6 min can up to 55 ℃.W hen magnetic bone cement placed i n the al terna ting magnetic field(390 KHz,21KA/m)at 50℃ for 30 min,the apoptotic rate of MG-63 cell s was77.78%,and 88%prolifera tion of bone tumor cells was inhibited.On the other hand,when magnet ic bone cement placed in the alternating magnetic fiel d(390 KHz,21KA/m)at for 6min,the apoptosis rate of M G-63 cell s was 80.78%,and 96%prolifera tion of bone tumor cells was inhibited.In addi tion,the cytotoxicity of magnet ic cement with 5% Co0.04Fe2.96O4 magnetic nanoparticles has no s ignificant differenc e betwee n the control group.4.The survival t ime of the control group was(27 ± 6)days.In the treatment group,two of the six rabbit s did not find recurrence,the other four occur ed recurrence,two of the four have dead at the 40 thday and the 43 thday,the other two have survived for 49 days(not yet dead).At the same t ime,the max imal diameter of the tum or was(42 ± 6.2)mm in the control group while(11.1 ± 5.5)mm in the treatment gr oup,which indicated t hat the effect of the inhibitionon of tumor growth rate was obvious.Conclusion:In this experiment,the prepare d Co0.04Fe2.96O4 at 22 nm has good magnetic properties,therm al perform ance and bi osafety.Magne tic bone cem ent with 5%C o0.04Fe2.9 6O4 magnetic nanoparticles pl aced i n the alternating magnetic field can not only induce the apoptosis of bone tumor cells but also inhibit t he prolifera ti on of bone tumor cell s effectively.In addi tion,it can also inhibit the gr owt h of bone tumors invivo effecti vely.Besides that,Magnetic bone cement with 5% C o0.04Fe2.96 O 4magnet ic nanoparticles has no side effect on rabbits’ liver and ki dney functions.This new typ e of magnetic bone cem ent has ex cellent therapeutic effects on bone tumor both in vivo and in vitro when placed i n alternating magnetic fiel d.What is more,it can addre ss the problem of pathologica l fracture deriving from bone tumor effectively and it provides a new idea for the treatment of bone t umors.