In vitro formation and characterization of a perfusable three-dimensional tubular capillary network in microfluidic devicesElectronic supplementary information (ESI) available: Fig. S1. Vascular fusion and capillary tube formation on the device. Fig. S2. Tubular and perfusable blood vessels. Fig. S3 Flow of FITC-dextran through the blood vessel. Fig. S4 Flow of RBCs through the blood vessel. Fig. S5 Method for counting loaded cells and vessel-forming cells. See DOI: 10.1039/c2lc40131b

• Main Authors: Yeon, Ju Hun, Ryu, Hyun Ryul, Chung, Minhwan, Hu, Qing Ping, Jeon, Noo Li
• Format: Article
• Language: English
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/c2lc40131b

This paper describes the in vitro formation and characterization of perfusable capillary networks made of human umbilical vein endothelial cells (HUVECs) in microfluidic devices (MFDs). Using this platform, an array of three-dimensional (3D) tubular capillaries of various dimensions (50-150 m in diameter and 100-1600 m in length) can be formed reproducibly. To generate connected blood vessels, MFDs were completely filled with fibrin gel and subsequently processed to selectively leave behind gel structures inside the bridge channels. Following gel solidification, HUVECs were coated along the gel walls, on opposite ends of the patterned 3D fibrin gel. After 3-4 days, HUVECs migrating into the fibrin gel from opposite ends fused with each other, spontaneously forming a connected vessel that expressed tight junction proteins ( e.g. , ZO-1), which are characteristic of post-capillary venules. With ready access to a perfusable capillary network, we demonstrated perfusion of the vessels and imaged red blood cells (RBCs) and beads flowing through them. The results were reproducible (50% successful perfusable capillaries), consistent, and could be performed in a parallel manner (9 devices per well plate). Additionally, compatibility with high resolution live-cell microscopy and the possibility of incorporating other cell types makes this a unique experimental platform for investigating basic and applied aspects of angiogenesis, anastomosis, and vascular biology. We demonstrated the in vitro formation and characterization of a perfusable capillary network made of HUVECs in microfluidic devices (MFDs). Using this platform an array of 3D tubular capillaries of various dimensions can be formed reproducibly and RBC and beads can flow through capillary vessels.