3D生物描绘孔结构可控钙磷硅基骨修复支架的生物力学性能

Biomechanical properties of calcium silicate / calcium phosphate cement scaffolds with controllable porous structure for bone repair by 3D bioplotting

目的设计和制备新型钙磷硅基骨修复支架，研究其在不同外力作用下体外生物力学性能。方法以自固化磷酸钙骨水泥（calcium phosphate cement，CPC）、介孔硅酸钙（mesporous calcium silicate，MCS）为原料，通过3D生物描绘技术构建孔径分别为350、500μm的MCS／CPC复合支架。采用扫描电镜观察支架表面形貌；分别通过万能力学试验机和动态力学分析仪，考察具有不同孔道结构MCS／CPC支架的抗压力学性能和不同频率动态周期性载荷作用下的力学性能。结果通过3D生物描绘技术能够实现对钙磷硅基骨修复支架内部孔道结构的可控制备。孔径为350μm的MCS／CPC支架具有较高的抗压力学强度[（9．80±0．39）MPa]和抗压模量[（132．50±4．30）MPa]；此外，载荷频率在1—100Hz范围内，孔径为350μm的支架具有较高的储能模量。结论通过3D生物描绘技术制备的孔径为350μm的MCS／CPC复合支架不仅具有规则的连通孔道，还具有较高的抗压力学性能，能在动态载荷作用下保持结构稳定，适合作为一种新型的骨缺损修复材料。

Objective To design and fabricate novel mesoporous calcium silicate/calcium phosphate cement （MCS/CPC） scaffolds for bone repair and investigate their in vitro biomechanical properties under different exter- nal forces. Methods MCS and CPC in certain proportion were mixed to form plotting material, and the composite MCS/CPC scaffolds with pore size of 350μm and 500 μm were fabricated by 3D bioplotting technique, respective- ly. Surface topographies of the scaffolds were observed by scanning electron microscope （SEM）. The compres- sive strength and mechanical properties of the scaffolds under dynamic cyclic loads at different frequencies werestudied through universal mechanical testing machine and dynamic mechanical analysis instrument. Results MCS/CPC scaffolds with controllable macroporous structures could be fabricated by 3D bioplotting technique. Scaffolds with pore size of 350 μm had higher compressive strength [ （9.8 -±0.39） MPa] and compressive modulus [ （132.5 ±4.3） MPa]. In addition, at the loading frequency of 1-100 Hz, scaffolds with pore size of 3,50 μ had a higher storage modulus. Conclusions MCS/CPC scaffolds with pore size of 350 μm fabricated by 3D bioplotting technique possess not only regular pore connectivity and high compressive strength, but also structural stability under dynamic loads, which are promising as novel biomaterials for bone repair.