Research On Preparation Of Ion Doped β-Tricalcium Phosphate Materials And Properties Of 3D Scaffolds

As a new bioactive ceramic material,β-tricalcium phosphate(β-TCP)has many advantages such as good biocompatibility and similar composition to human bone,which has become an important development material for tooth restoration and bone treatment of defects.However,due to its low mechanical properties,β-TCP has not been applied in clinical treatment so far.Recently,many scholars are committed to improving the properties of β-TCP through composite and ion doping modification methods.Magnesium and manganese,as essential elements for the growth of the body,have a positive effect on the growth of human bone tissue.S ome research showed that the doping of magnesium ions could improve the thermal stability ofβ-TCP,and the doping of manganese ions could promote the sintering of β-TCP as well as improve its mechanical properties.In recent years,3D printing technology has been widely used in bone tissue engineering due to its high dimensional accuracy and great ability of manufacting complex structures.In this paper,the modification of β-TCP material was cleverly combined with 3D printing technology to research on the preparation of ion-doped β-TCP and the properties of 3D scaffolds,which will promote the application and development of β-TCP material as well as3 D printing technology in the field of bone tissue engineering.In this paper,β-TCP was prepared by acid-base neutralization method.The theoretical analysis of this method was carried out from the perspectives of chemical reaction principle,kinetics and thermodynamics,respectively.The acid and alkali neutralization reaction mechanism to prepare β-TCP was identified,and the reaction process parameters were optimized;Moreover,the practical significance,feasibility and doping mechanism of ion doping were emphatically analyzed from the perspectives of biology and materials science;the experimental scheme of magnesium,manganese ions doping was determined,which laid a solid theoretical foundation for the follow-up experimental research.The magnesium chloride,manganese chloride was firstly used as the source of preparation of the co-doped Mg and Mn ions of β-TCP ceramic material,the influence of both the variety of ion doping and the doping concentration on β-TCP material phase composition,microstructure,particle size,concentration,and the regular of phase transition were systemly analysised.It was fou nd that the maximum doping amount of magnesium ion,manganese ion,magnesium and manganese co-doped was Mg7%,Mn10% and Mg4%Mn4%,respectively;the phase of the material would transform into others when the doping ion amount exceeding these ratio.Ion doping can strengthen the bonding effect between powder particles and lead to sintering neck,which proves the effect of ion doping on material sintering.Thermal analysis was carried out on the co-doped Mg and Mn ions of β-TCP material,and it was found that the phase transition temperature would dec rease with the increase of ion doping concentration,proving that ion doping could enhance the thermal stability of β-TCP.The 3D printing technology of grouting molding has achieved the preparation of 3D porous bone scaffolds with controllable pore structure and components,as well as good formability.The effects of printing parameters,sintering system and ion doping concentration on the physical and chemical properties,mech anical properties of scaffolds were studied,the degradation properties were tested by in vitro degradation and mineralization experiments.The results showed that the sintering system and ion doping had a great influence on the mechanical properties of scaffolds.With the increase of sintering temperature,the mechanical properties of the scaffolds were improved.The compressive strength of the scaffolds sintered at1200 °C reached the highest,about 4.33 MPa.Ion doping can also significantly improve the mechanical properties of the scaffolds.The compressive strength of Mg3%Mn3% scaffolds are the highest,about 9.81 MPa.The results of Tris-HCl degradation experiment in vitro showed that the mass loss of the scaffold s after 14 days of soaking was up to 20%,which proved that the scaffolds had good degradation performance.The results of SBF mineralization experiment in vitro showed that there was obvious apatite layer deposition on the surface of the scaffold S after 14 days of soaking,which proved that the scaffolds have good ability to induce the formation of bone-like apatite,which showed good biocompatibility.