To make organoids more like real organs, they must be vascularized. Vascular channels can be engineered into tissue cultures by 3D printing techniques that lay down channels that can be lined with human endothelial cells (HUVEC) within a gel matrix containing human fibroblasts (HDNF). Cell printing is shown on top: In A a print head is laying down one of three kinds of cells in a pattern (inset); B shows the final product. However, we want vessels to grow into the organoids and so are developing ways of leveraging the natural propensity of endothelial vessels to sprout new vessels, as shown at the bottom (C-E).
(Images courtesy of the Lewis Lab.)
(Images courtesy of the Lewis Lab.)