Synthesis And Characterization Of Nano ?-tricalcium Phosphate With Multiple Ions Substitution

As a biodegradable bone repair material,?-tricalcium phosphate?-TCP has attracted extensive attention due to its good biocompatibility and bioconductivity.In addition to Ca²⁺and PO₄^3-,there are many other functionalized ions in natural bone,such as Mg²⁺,Sr²⁺.They play a critical role in the process of osteogenesis.Therefore,doping other ions into?-TCP can help improve the osteogenic ability of?-TCP.Due to the special crystallization behavior of?-TCP,it is difficult to obtain nanoscale products by traditional methods.The difference of the microwave heating process from the tranditional heating is that heatis geberated inside the object so that heating speed is fast and the materials is heated homogeneously.It is favorable for the synthesis of particles with uniform morphology and smaller size.In this study,on the basis of traditional chemical precipitation method,microwave was assisted to synthesize different ions doped nano?-TCP,the specific content is as follows:Explore the best microwave synthesis conditions and synthesize?-TCP with different Mg²⁺contents.Firstly,Mg-5mol%doped sample was synthesized under different microwave conditions to discuss the effects of microwave temperature and time on the phase,morphology and particle size.Through the analysis of XRD,FT-IR,SEM,TEM,etc.,it was found that the microwave temperature 40,time 20 min was the most suitable microwave parameters,in which?-TCP phase was harvested with 80nm-diameter and uniform morphology.Then?-TCP with different Mg²⁺substitution?0,5,10,14 mol%?were synthesized in this condition.The results showed that the substitution of Mg²⁺did not affect the phase of?-TCP,but altered the cell parameters and volume.In order to investigate the effect of different Mg²⁺contents on proliferation and differentiation,the powder of Mg²⁺doped?-TCP was synthesized into extracts and ceramic discs to culture rats bone mesenchymal stem cells?BMSCs?.The results showed that Mg²⁺could promote cell proliferation and differentiation,but when the doping amount was 5,10mol%,Ca²⁺and Mg²⁺in the medium decreased due to dissolution-deposition process between the ceramic discs and the medium,thus the effects of promotion is not significant.When Mg²⁺content reached 14 mol%,during the long-time direct effects between ceramic discs and cells,more Mg²⁺was released from the materials into the culture medium,which significantly promoted the proliferation and differentiation of BMSCs.The same method as in chapter 2 was used to prepare Sr doped?6mol%?and Mg/Sr co-doped?6mol%:6mol%??-TCP,and they were characterized it by XRD,SEM,TEM and ICP to discuss the influence of Sr and Mg/Sr co-doped on?-TCP.The results showed that when Sr was incoeparated into structure,the product was?-TCP in the same conditions,and when Mg/Sr co-doped,no change of?-TCP phase and no significant change of morphology were observed.However,due to the influence of ion radius and substitution position,the cell parameters of the product was altered.