Abstract
[Background] Tissue engineering is expected to create organs or tissue in vitro for medical treatment. For clinical applications, tissue is needed to integrate capillary network. However, tissue created in vitro doesn't have any vascular vessel, which supplies nutrition and oxygen to cells, so practical sizes of 3D tissue aren't built up to now. Vessels are formed a hierarchical structure, but the mechanism determining the diameter is still unclear. [Materials and Methods] We tried to control the diameter of vessel, using microfluidic device. In opposite seeding condition, human umbilical vein endothelial cells (HUVECs) and mesenchymal stem cells (MSCs) were seeded in the different microfluidic channels, respectively. In same seeding condition, both of them were seeded in the same microfluidic channel. We evaluated the diameter of created vascular vessels in each condition. [Results] In opposite seeding, the diameter was 19 μm on Day 10, and becoming narrower day by day. When we added VEGF gradient in opposite seeding, vessels were enlarged on Day 10. In same seeding, the diameter was less than 10 μm through Day 10 to Day 21, its size was similar to opposite seeding on Day 21.
