Deng Pengwei, Zhao Mengqian, Zhang Xu, Qin Jianhua
Division of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Bioengineering (Basel). 2022 Nov 8;9(11):668. doi: 10.3390/bioengineering9110668.
Interstitial flow plays a significant role in vascular system development, mainly including angiogenesis and vasculogenesis. However, compared to angiogenesis, the effect of interstitial flow on vasculogenesis is less explored. Current in vitro models for investigating the effect of interstitial flow on vasculogenesis heavily rely on microfluidic chips, which require microfluidic expertise and facilities, and may not be accessible to biological labs. Here, we proposed a facile approach to building perfusable vascular networks through the self-assembly of endothelial cells in a modified transwell format and investigated the effect of interstitial flow on vasculogenesis. We found that the effect of interstitial flow on vasculogenesis was closely related to the existence of VEGF and fibroblasts in the developed model: (1) In the presence of fibroblasts, interstitial flow (within the range of 0.1-0.6 μm/s) facilitated the perfusability of the engineered vasculatures. Additional VEGF in the culture medium further worked synergically with interstitial flow to develop longer, wider, denser, and more perfusable vasculatures than static counterparts; (2) In the absence of fibroblasts, vasculatures underwent severe regression within 7 days under static conditions. However, interstitial flow greatly inhibited vessel regression and enhanced vascular perfusability and morphogenesis without the need for additional VEGF. These results revealed that the effect of interstitial flow might vary depending on the existence of VEGF and fibroblasts, and would provide some guidelines for constructing in vitro self-assembled vasculatures. The established transwell-based vascularized model provides a simple method to build perfusable vasculatures and could also be utilized for creating functional tissues in regenerative medicine.
间质流在血管系统发育中起着重要作用，主要包括血管生成和血管发生。然而，与血管生成相比，间质流对血管发生的影响研究较少。目前用于研究间质流对血管发生影响的体外模型严重依赖微流控芯片，这需要微流控专业知识和设备，生物实验室可能无法获得。在此，我们提出了一种简便的方法，通过在内皮细胞以改良的Transwell形式自组装来构建可灌注的血管网络，并研究间质流对血管发生的影响。我们发现，间质流对血管发生的影响与所构建模型中VEGF和成纤维细胞的存在密切相关：（1）在成纤维细胞存在的情况下，间质流（在0.1 - 0.6μm/s范围内）促进了工程化血管的可灌注性。培养基中额外的VEGF进一步与间质流协同作用，使血管比静态对照组更长、更宽、更密集且更具可灌注性；（2）在没有成纤维细胞的情况下，血管在静态条件下7天内严重退化。然而，间质流极大地抑制了血管退化，并增强了血管的可灌注性和形态发生，而无需额外的VEGF。这些结果表明，间质流的影响可能因VEGF和成纤维细胞的存在而有所不同，并将为构建体外自组装血管提供一些指导。所建立的基于Transwell的血管化模型提供了一种构建可灌注血管的简单方法，也可用于再生医学中创建功能性组织。
