多孔硅酸钙/明胶复合支架制备工艺及力学性能研究

Fabrication Process and Mechanical Performance of Porous Calcium Silicate/Gelatin Composite Scaffold

针对可控复杂孔隙结构的多孔生物陶瓷支架难以通过传统方法制备、强度低、脆性大等问题,提出了一种将光固化工艺和渗透明胶工艺相结合的方法,制备了具有优异力学性能的多孔硅酸钙/明胶复合支架。通过扫描电子显微镜研究了不同明胶质量浓度复合支架的微观结构,探讨了明胶溶液质量浓度对多孔硅酸钙/明胶复合支架Z向和X-Y向力学性能的影响规律。结果表明:渗透明胶后,明胶填充了支架的部分微观孔隙并涂覆在支架表面。当明胶质量分数为5%和7.5%时,试样宏观孔隙连通性较好,强度和韧性得到了明显提高。此质量浓度范围下复合支架仍存在各向异性,在Z向的压缩强度提高了0.63~1.67倍,最高达到5.91 MPa,应力能密度提高了0.84~1.77倍,最高达到530×10^(4) J/m^(3);X-Y向的压缩强度提高了1.56~2.07倍,最高达到10.01 MPa,应力能密度提高了1.51~3.33倍,最高达到10.75×10^(4) J/m^(3)。因此,明胶质量分数为5%~7.5%是制备多孔硅酸钙/明胶复合支架的合适浓度。

To solve the poor mechanical performance and difficulty of fabrication of controllable complex porous bioceramic bone scaffolds by traditional methods,porous calcium silicate/gelatin composite scaffolds with excellent mechanical performance were developed with a two-step process:fabricating the porous calcium silicate scaffolds by digital light processing(DLP);immersing the porous calcium silicate scaffolds into a gelatin melt.The microstructure of composite scaffolds with different gelatin contents was observed by scanning electron microscope.The effects of gelatin contents on the mechanical performance in Z and X-Y directions of the porous calcium silicate/gelatin composite scaffolds were analyzed.The results show that gelatin fills the microscopic pores and coats the surface of the scaffolds.When the gelatin mass fraction gets 5%and 7.5%,the samples are endowed with good pore connectivity,mechanical strength and toughness.However,the composite scaffolds still exhibit mechanical anisotropy.The compressive strength and strain energy density in the Z direction are increased by 0.63-1.67 times to 5.91 MPa and by 0.84-1.77 times to 5.30×10^(4) J/m^(3),respectively.The compressive strength and strain energy density in the X-Y direction are increased by 1.56-2.07 times to 10.01 MPa and by 1.51-3.33 times to 10.75×10^(4) J/m^(3),respectively.Thus,the appropriate gelatin content for preparing porous calcium silicate/gelatin composite scaffold is chosen as 5%-7.5%.