利用同轴3D打印技术构建促内皮细胞生长类血管组织工程支架

体外构建血管网络对组织工程领域厚组织与器官再生至关重要。利用同轴3D打印技术,以海藻酸钠/丝素蛋白为生物墨水,可快速制备含人脐静脉内皮细胞(HUVECs)的类血管组织工程支架。首先通过材料压缩模量和可打印性测试,优化适用于同轴系统的材料浓度;然后通过光学相干层析成像技术,研究打印参数对中空纤维丝形状的影响,优化同轴打印参数;结合模拟灌流实验,对支架内部类血管结构进行表征;最后通过细胞活、死染色和Alamar Blue法,检测支架中HUVECs生长情况。结果表明,经优化的生物墨水及打印参数能顺利制备具有内部联通性完整的类血管组织工程支架;HUVECs在体外培养时存在团聚生长现象,类血管通道的存在有利于维持组织整体活性,一周存活率在97%以上,且相比对照组能够维持较高的增殖速率。研究证明,利用同轴3D打印技术能成功构建促内皮细胞生长的类血管组织工程支架,可为厚组织及器官再生提供新的可能。

Coaxial 3D Bioprinting of Vascular Tissue Engineering Scaffolds forPromoting Endothelial Cell Growth

In the field of tissue engineering, the construction of vascular networks in vitro is very important for the regeneration of thick tissue and organs. In this study, with alginate/silk fibroin as bioink, vascular tissue engineering scaffolds containing human umbilical vein endothelial cells (HUVECs) were rapidly prepared by coaxial 3D bioprinting. Firstly, the optimal concentration of materials for coaxial system were determined through compression modulus and printability test. Then, the effects of coaxial printing parameters on the shape of hollow fiber were studied by using optical coherence tomography, and the parameters were optimized. Combined with the simulated perfusion experiment, the vascular structure was characterized. Finally, the growth of HUVECs in the scaffolds was verified by cell live/dead staining and Alamar Blue method. Results showed that the optimized bioink and printing parameters could successfully prepare vascular tissue engineering scaffolds with complete internal connectivity. The HUVECs showed agglomeration growth in vitro, and the presence of vascularization channels was beneficial to maintain overall tissue activity, with a one-week survival rate of more than 97% and a higher proliferation rate than the control group. Our study proved that the vascular tissue engineering scaffolds built by coaxial 3D bioprinting technology promoted endothelial cell growth, providing new possibilities for thick tissue and organ regeneration.