Kiziltay Aysel, Marcos-Fernandez Angel, San Roman Julio, Sousa Rui A, Reis Rui L, Hasirci Vasif, Hasirci Nesrin
BIOMATEN-Centre of Excellence in Biomaterials and Tissue Engineering, Middle East Technical University (METU), Ankara, Turkey.
Graduate Department of Biotechnology, Middle East Technical University (METU), Ankara, Turkey.
J Tissue Eng Regen Med. 2015 Aug;9(8):930-42. doi: 10.1002/term.1848. Epub 2013 Dec 26.
The present study aimed to investigate the effect of structure (design and porosity) on the matrix stiffness and osteogenic activity of stem cells cultured on poly(ester-urethane) (PEU) scaffolds. Different three-dimensional (3D) forms of scaffold were prepared from lysine-based PEU using traditional salt-leaching and advanced bioplotting techniques. The resulting scaffolds were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mercury porosimetry and mechanical testing. The scaffolds had various pore sizes with different designs, and all were thermally stable up to 300 °C. In vitro tests, carried out using rat bone marrow stem cells (BMSCs) for bone tissue engineering, demonstrated better viability and higher cell proliferation on bioplotted scaffolds compared to salt-leached ones, most probably due to their larger and interconnected pores and stiffer nature, as shown by higher compressive moduli, which were measured by compression testing. Similarly, SEM, von Kossa staining and EDX analyses indicated higher amounts of calcium deposition on bioplotted scaffolds during cell culture. It was concluded that the design with larger interconnected porosity and stiffness has an effect on the osteogenic activity of the stem cells.
本研究旨在探讨结构（设计和孔隙率）对在聚（酯 - 聚氨酯）（PEU）支架上培养的干细胞的基质刚度和成骨活性的影响。使用传统的盐析法和先进的生物打印技术，由基于赖氨酸的PEU制备了不同三维（3D）形式的支架。通过差示扫描量热法（DSC）、热重分析（TGA）、扫描电子显微镜（SEM）、压汞法和力学测试对所得支架进行了表征。这些支架具有不同设计的各种孔径，并且在高达300°C的温度下均具有热稳定性。使用大鼠骨髓干细胞（BMSC）进行骨组织工程的体外试验表明，与盐析支架相比，生物打印支架上的细胞活力更好且细胞增殖更高，这很可能是由于其更大且相互连通的孔隙以及更硬的性质，压缩测试测得的压缩模量更高就表明了这一点。同样，SEM、冯·科萨染色和能谱分析表明，在细胞培养过程中，生物打印支架上的钙沉积量更高。得出的结论是，具有更大相互连通孔隙率和刚度的设计对干细胞的成骨活性有影响。
