改进粒子沥滤法制备PLA径向梯度多孔支架

Preparation of Poly(Lactic Acid) Scaffolds with a Radial Gradient Structure by a Modified Solvent Casting/porgen Leaching Method

采用溶剂浇铸/真空挥发/粒子沥滤法制备了径向梯度聚乳酸(PLA)多孔支架材料,对支架孔的形貌、孔径、孔隙率、压缩模量及致孔剂和溶剂残留情况等进行了研究.SEM测试结果表明,支架的孔分布均匀,孔径呈现梯度变化,且孔与孔间具有良好的相互连通性.梯度多孔支架各层的平均孔径在(175±30)～(341±23)μm之间;孔隙率均大于(87.9±1.2)%,结果表明:径向各层的孔径、孔隙率可通过致孔剂用量和粒径进行控制.压缩模量在(1.96±0.24)～(2.40±0.1)MPa之间,致孔剂用量和致孔剂粒径的变化均会导致支架力学性能的变化;TGA测试结果证实支架不存在致孔剂和溶剂残留.

PLA porous gradient materials were prepared by a solvent casting/vacuum volatilization/porogenleaching （SC/VV/PL） method. The pore morphology, pore size, porosity and compression modulus ofthe scaffolds were studied. The TGA was used to test the quantities of salts and solvent remained insidethe graded scaffold. The results of SEM showed that the scaffold had homogeneous pores distribution, anda better connectivity was found between pores and pores. The average pore sizes of each layer are from 175±30μm to 341±23μm, and the porosity is up to 87.9±1.2%, which showed that each layer＇s pore sizeand porosity can be controlled by changing the particle size and the amount of the porogen. The compres-sion moduli are between 1.96±0.24MPa and 2.40±0.1MPa. The results of TGA confirmed that therewas no obvious residual of salts and solvent in the resultant scaffolds. This method allows the fabricationof radial grade macroporous PLA scaffold in a simple, homogenous, and fast way.