Fabrication of PCL Scaffolds by Supercritical CO2 Foaming Based on the Combined Effects of Rheological and Crystallization Properties
Fabrication of PCL Scaffolds by Supercritical CO2 Foaming Based on the Combined Effects of Rheological and Crystallization Properties
复制标题
基于流变性能和结晶性能综合作用的超临界CO2发泡制备PCL支架
DOI：
10.3390/polym12040780
复制
发表时间：
2020-04-01
期刊：
影响因子：
5
通讯作者：
Lu, Eryi
中科院分区：
文献类型：
--
作者：
Song, Chaobo;Luo, Yunhan;Lu, Eryi
聚己内酯(PCL)支架最近通过高效绿色的超临界二氧化碳(ScCO2)熔融发泡法开发出来。然而，以前报道的气体泡沫支架有时显示出不足以用于组织工程的互连性或孔径。在这项研究中，我们通过研究四个不同相对分子质量(MW)的发泡样品，研究了PCL支架的热学和流变性与其多孔形态之间的关系，特别是旨在阐明制备具有良好互联大孔的支架所需的性质。差示扫描量热法(DSC)和流变学测试表明，随着相对分子质量的增加，样品呈现延迟结晶和复粘度增大的趋势。发泡后，重均分子质量为27μ的支架具有良好的形貌(孔径为70-180 kDa m，孔隙率为90%，连通性为96%)，熔体强度最低有利于连通大孔的生成，最快的结晶提供了合适的发泡性。支架(27 KDa)也具有最高的杨氏弹性系数。更重要的是，由于高度连通的大孔提供了足够的空间和良好的材料运输，细胞在优化的支架(27 KDa)上表现出强劲的增殖和良好的粘附性和内生性，表明其具有再生应用的潜力。此外，我们的发现为通过scCO2发泡制造的多孔支架的形态控制提供了新的见解，并与关注聚合物发泡的更广泛的社区高度相关。
Polycaprolactone (PCL) scaffolds have recently been developed via efficient and green supercritical carbon dioxide (scCO2) melt-state foaming. However, previously reported gas-foamed scaffolds sometimes showed insufficient interconnectivity or pore size for tissue engineering. In this study, we have correlated the thermal and rheological properties of PCL scaffolds with their porous morphology by studying four foamed samples with varied molecular weight (MW), and particularly aimed to clarify the required properties for the fabrication of scaffolds with favorable interconnected macropores. DSC and rheological tests indicate that samples show a delayed crystallization and enhanced complex viscosity with the increasing of MW. After foaming, scaffolds (27 kDa in weight-average molecular weight) show a favorable morphology (pore size = 70–180 μm, porosity = 90% and interconnectivity = 96%), where the lowest melt strength favors the generation of interconnected macropore, and the most rapid crystallization provides proper foamability. The scaffolds (27 kDa) also possess the highest Young’s modulus. More importantly, owing to the sufficient room and favorable material transportation provided by highly interconnected macropores, cells onto the optimized scaffolds (27 kDa) perform vigorous proliferation and superior adhesion and ingrowth, indicating its potential for regeneration applications. Furthermore, our findings provide new insights into the morphological control of porous scaffolds fabricated by scCO2 foaming, and are highly relevant to a broader community that is focusing on polymer foaming.