Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
Mater Sci Eng C Mater Biol Appl. 2013 May 1;33(4):2094-103. doi: 10.1016/j.msec.2013.01.025. Epub 2013 Jan 20.
The physical properties of tissue engineering scaffolds such as microstructures play important roles in controlling cellular behaviors and neotissue formation. Among them, the pore size stands out as a key determinant factor. In the present study, we aimed to fabricate porous scaffolds with pre-defined hierarchical pore sizes, followed by examining cell growth in these scaffolds. This hierarchical porous microstructure was implemented via integrating different pore-generating methodologies, including salt leaching and thermal induced phase separation (TIPS). Specifically, large (L, 200-300 μm), medium (M, 40-50 μm) and small (S, <10 μm) pores were able to be generated. As such, three kinds of porous scaffolds with a similar porosity of ~90% creating pores of either two (LS or MS) or three (LMS) different sizes were successfully prepared. The number fractions of different pores in these scaffolds were determined to confirm the hierarchical organization of pores. It was found that the interconnectivity varied due to the different pore structures. Besides, these scaffolds demonstrated similar compressive moduli under dry and hydrated states. The adhesion, proliferation, and spatial distribution of human fibroblasts within the scaffolds during a 14-day culture were evaluated with MTT assay and fluorescence microscopy. While all three scaffolds well supported the cell attachment and proliferation, the best cell spatial distribution inside scaffolds was achieved with LMS, implicating that such a controlled hierarchical microstructure would be advantageous in tissue engineering applications.
组织工程支架的物理特性，如微观结构，在控制细胞行为和新组织形成方面起着重要作用。其中，孔径是一个关键的决定因素。在本研究中，我们旨在制造具有预定义分级孔径的多孔支架，并研究细胞在这些支架中的生长情况。这种分级多孔微结构是通过整合不同的孔生成方法来实现的，包括盐浸出和热诱导相分离（TIPS）。具体来说，可以产生大（L，200-300μm）、中（M，40-50μm）和小（S，<10μm）孔。因此，成功制备了三种具有相似孔隙率（~90%）的多孔支架，这些支架的孔径分别为两种（LS 或 MS）或三种（LMS）不同大小的孔。通过确定不同孔径在支架中的数量分数，证实了孔径的分级组织。发现由于不同的孔结构，连通性会有所不同。此外，这些支架在干燥和水合状态下具有相似的压缩模量。通过 MTT 测定法和荧光显微镜评估了人成纤维细胞在支架中 14 天培养期间的黏附、增殖和空间分布。虽然所有三种支架都能很好地支持细胞附着和增殖，但在 LMS 中实现了最佳的细胞空间分布，这表明这种受控的分级微结构在组织工程应用中是有利的。
