3D Printing Of Porous ?-TCP Bioactive Ceramic

Bone defect is one of the most common diseases in clinical medicine.With the serious aging of the population and the improvement of people's living and medical level,the demand for bone implants is increasing year by year.In the aspect of bone defect repair and regeneration,bone tissue engineering has unique advantages besides the "gold standard" autogenous bone transplantation.The core of bone tissue engineering lies in the construction of scaffolds with good biocompatibility,promoting the formation of new bone tissue,high porosity,and meeting the mechanical properties of application sites.Beta-tricalcium phosphate is mainly composed of calcium and phosphorus.The ratio of calcium to phosphorus is 1.5.It has good biocompatibility,biodegradability,bone conduction and bone induction ability.It has attracted wide attention in the field of bone tissue engineering.However,there are many limitations in traditional preparation of porous beta-tricalcium phosphate scaffolds,which make it difficult to construct through-pore and control pore structure.This problem can be well solved by the rapid increment manufacturing technology developed in recent years.In this paper,firstly,a large number of beta-tricalcium phosphate powders with well crystallinity,high purity and uniform particle size were successfully prepared.Ceramic inks suitable for 3D printing were prepared with sodium alginate and Planick F-127 as printing aids.Porous ceramic scaffolds with 50%-67% porosity were prepared by 3D printing equipment.The flowablity of ceramic inks was characterized by rheometer and consistency meter.The micro-pore structure and mechanical properties of different porous ceramics scaffolds were evaluated by scanning electron microscopy(SEM)and universal capability testing machine.The ceramic scaffolds with 50% solid content of beta-tricalcium phosphate exhibited good porosity and mechanical properties,with porosity of 57.5%,compressive strength of 22.3 MPa.Then,the porous ?-tricalcium phosphate ceramic scaffolds were prepared by adding bioglass,and the effect of bioglass on the micropore morphology,mechanical properties and degradation activity of ?-tricalcium phosphate scaffold was discussed.Firstly,bioglass powder with particle size distribution of 1-2?m was prepared by melting method and high energy ball milling,and then 5 wt%-20 wt% bioglass powder was added during the preparation of ceramic 3D printing ink,which was formed by 3D printing equipment,the microstructure,phase composition,mechanical properties and degradation properties of the scaffolds sintered at 710 °C were tested,the results show that with the increase of bioglass addition,the mechanical properties and degradability of ?-tricalcium phosphate porous ceramic scaffolds are enhanced.The ?-tricalcium phosphate porous ceramic scaffold with 20 wt% bioglass addition showed the best mechanical properties and degradation rate,the compressive strength and elastic modulus were 8.34 MPa,208.5 MPa,respectively,the degradation rate was improved by 2.99 times relative to the pure ?-tricalcium phosphate porous ceramic scaffold.Finally,the cytocompatibility of the prepared ?-tricalcium phosphate porous ceramic scaffolds were preliminarily evaluated.The results showed that the scaffolds had no obvious cytotoxicity to MC3T3-E1 cells,and the addition of bioglass promoted the proliferation of MC3T3-E1 cells.Bone marrow mesenchymal stem cells(rBMSCs)have good adhesion and the the ?-tricalcium phosphate porous ceramic scaffold with bioglass addition showed an induce effect on osteogenic differentiation of bone marrow mesenchymal stem cells.