Construction of vasculature structure within fluidic channel using three-dimensional bio-printer

Vascularization for sufficient supplies of oxygen/nutrients and removal of waste in thicker tissue is one of the major challenges in tissue engineering. Here, we used three-dimensional bio-printing technology to engineer a vascular structure within hydrogel scaffold. Through layer-by-layer approach, we seeded endothelial cells in tubular form, which is embedded within three-dimensional collagen scaffold. Collagen hydrogel precursor was printed and polymerized. Endothelial cells in heated gelatin hydrogel were printed within the collagen scaffold, subsequently gelatin was liquefied and washed out in order to fabricate a fluidic channel with endothelial cell lining. The channels were connected to perfusion system. Specially-designed flow chamber was used for stable perfusion. The endothelial cells survived under flow condition, showing high viability and integration along the channel wall. The channel had a width 400–700 um, and was able to resist 200mmHg of pressure. Functional assessments of the printed vascular channels are in progress. We have demonstrated the capability of using three-dimensional bio-printing technology in rapid, simple, and highthroughput vasculature formation. The process has a potential application in vascular tissue engineering and study in angiogenesis.