填充结构对3D打印聚己内酯支架力学性能的影响

Influence of lay-down angles on mechanical properties of three-dimensional printed polycaprolactone scaffolds

背景:3D打印聚己内酯组织工程支架是近些年来研究的热点之一,选择合适的材料制备力学性能优良的多孔支架是当前研究的难点。目的:制备不同填充结构的三维多孔聚己内酯支架,研究其机械性能。方法:设计0°/90°、0°/60°、0°/60°/120°、0°/45°和0°/45°/90°/135°5种填充结构,采用生物3D打印机打印三维多孔聚己内酯支架,测试支架的孔隙率及压缩和拉伸性能。结果与结论:(1)5种支架的孔隙率比较差异无显著性意义(P>0.05);(2)从Z方向压缩时,不同填充结构聚己内酯支架的压缩性能差异很小;(3)从Y方向压缩时,0°/45°、0°/60°、0°/90°三种支架的压缩性能随填充角度增加而增强,0°/45°/90°/135°支架的压缩模量和强度比0°/45°支架高,0°/60°/120°支架的压缩模量和强度比0°/60°支架强;(4)从X方向压缩时,支架压缩模量和强度的规律与Y方向压缩相反;在5种支架中,0°/45°/90°/135°支架的拉伸模量和强度最大,0°/90°支架的拉伸模量和强度最小,0°/45°、0°/60°、0°/90°支架的拉伸强度和模量随角度增加而减小;(5)结果表明,0°/90°和0°/60°/120°填充结构的支架可满足力学性能各向同性的生理环境需求,其他3种结构可满足人体组织各向异性生长环境的要求。

BACKGROUND: Three-dimensional(3 D) printed polycaprolactone scaffold is one of the hotspots in recent years. It is difficult to prepare porous scaffolds with appropriate materials and excellent mechanical properties in current studies. OBJECTIVE: To manufacture 3 D porous polycaprolactone scaffolds with different lay-down angles and study their mechanical properties.METHODS: 3 D porous polycaprolactone scaffolds with different lay-down angles(0°/90°, 0°/60°, 0°/60°/120°, 0°/45° and 0°/45°/90°/135°) were designed and prepared using 3 D printer. The porosity, compression and tensile properties of the scaffold were measured.RESULTS AND CONCLUSION:(1) There was no significant difference in the porosity of the five scaffolds(P > 0.05).(2) In Z direction compression, there was little difference for polycaprolactone scaffolds with different lay-down angles.(3) In Y direction, the compression of the 0°/45°, 0°/60°, and 0°/90° scaffolds increased with the increase of the filling angle. The compressive modulus and strength of 0°/45°/90°/135° were higher than those of 0°/45°. The compressive modulus and strength of 0°/60°/120° scaffolds were stronger than those of 0°/60°.(4) When the three scaffolds were compressed in X direction, the law of the compression modulus and strength of the scaffold was opposite to those of the compression in the Y direction. Among the five types of scaffolds, the tensile modulus and strength of the 0°/45°/90°/135° scaffolds were the largest, and the tensile modulus and strength of the 0°/90° scaffold were the smallest;the tensile strength and modulus of the 0°/45°, 0°/60°, and 0°/90° scaffolds decreased with the increase of the angle.(5) The results show that the 0°/90° and 0°/60°/120° scaffolds can meet the requirements of the physiological environment with isotropic mechanical properties, and the other three structures can meet the requirements of the anisotropic growth environment of human tissues.