National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran.
Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom.
Biomed Mater. 2022 Jun 22;17(4). doi: 10.1088/1748-605X/ac7308.
The aim of this paper was to design and fabricate a novel composite scaffold based on the combination of 3D-printed polylactic acid-based triply periodic minimal surfaces (TPMSs) and cell-laden alginate hydrogel. This novel scaffold improves the low mechanical properties of alginate hydrogel and can also provide a scaffold with a suitable pore size, which can be used in bone regeneration applications. In this regard, an implicit function was used to generate some gyroid TPMS scaffolds. Then the fused deposition modeling process was employed to print the scaffolds. Moreover, the micro computed tomography technique was employed to assess the microstructure of 3D-printed TPMS scaffolds and obtain the real geometries of printed scaffolds. The mechanical properties of composite scaffolds were investigated under compression tests experimentally. It was shown that different mechanical behaviors could be obtained for different implicit function parameters. In this research, to assess the mechanical behavior of printed scaffolds in terms of the strain-stress curves on, two approaches were presented: equivalent volume and finite element-based volume. Results of strain-stress curves showed that the finite-element based approach predicts a higher level of stress. Moreover, the biological response of composite scaffolds in terms of cell viability, cell proliferation, and cell attachment was investigated. In this vein, a dynamic cell culture system was designed and fabricated, which improves mass transport through the composite scaffolds and applies mechanical loading to the cells, which helps cell proliferation. Moreover, the results of the novel composite scaffolds were compared to those without alginate, and it was shown that the composite scaffold could create more viability and cell proliferation in both dynamic and static cultures. Also, it was shown that scaffolds in dynamic cell culture have a better biological response than in static culture. In addition, scanning electron microscopy was employed to study the cell adhesion on the composite scaffolds, which showed excellent attachment between the scaffolds and cells.
本文旨在设计和制造一种基于 3D 打印聚乳酸基三重周期性极小曲面（TPMS）与细胞负载海藻酸钠水凝胶结合的新型复合支架。这种新型支架提高了海藻酸钠水凝胶的低机械性能，同时也提供了具有合适孔径的支架，可用于骨再生应用。在这方面，使用隐式函数生成了一些蛋型 TPMS 支架。然后采用熔融沉积建模工艺打印支架。此外，还采用微计算机断层扫描技术评估 3D 打印 TPMS 支架的微观结构，并获得打印支架的真实几何形状。通过压缩试验对复合支架的力学性能进行了实验研究。结果表明，不同的隐式函数参数可以获得不同的力学行为。在这项研究中，为了根据应变-应力曲线评估打印支架的力学行为，提出了两种方法：等效体积和基于有限元的体积。应变-应力曲线的结果表明，基于有限元的方法预测的应力水平更高。此外，还研究了复合支架在细胞活力、细胞增殖和细胞附着方面的生物学反应。为此，设计并制造了一个动态细胞培养系统，该系统通过复合支架改善了质量传递，并对细胞施加机械载荷，有助于细胞增殖。此外，将新型复合支架的结果与不含海藻酸钠的支架进行了比较，结果表明复合支架在动态和静态培养中均能产生更高的细胞活力和增殖。同时，还表明动态细胞培养中的支架具有比静态培养更好的生物学响应。此外，还采用扫描电子显微镜研究了细胞在复合支架上的附着情况，结果表明支架与细胞之间具有极好的附着性。
