For more information on EB culture procedures, see Jakobsson et al. 1, C and E), or into a 3D collagen gel ( Fig. The hanging drop culture proceeds for a few days to allow EB growth and differentiation, followed by seeding into a two-dimensional (2D) culture ( Fig. 1, A and B), after the removal of feeder cells and leukemia inhibitory factor that otherwise are used to keep the ESCs pluripotent. Vascular development and sprouting angiogenesis in embryoid bodiesįormation of EBs can be controlled through aggregation of ESCs in hanging drops ( Fig. To this end, it is essential to create easily accessible models by which vessel development can be both manipulated and studied at high resolution. There are currently considerable efforts invested into the development of drugs aimed to control blood vessel growth in conditions such as ischemia and cancer, characterized by deficient or excessive vessel growth, respectively. Angiogenesis is a tightly controlled process where EC proliferation and migration is regulated by secreted factors as well as by surrounding cells and matrix. The outside of the endothelium is covered with a specialized layer of connective tissue (the basement membrane) followed by a layer of mural cells (pericytes and vascular smooth muscle cells). The inside of blood vessels is lined with endothelium, a thin layer of endothelial cells (ECs), which separates the blood from tissues. All blood vessels share a number of basic features, although the detailed gene expression pattern, morphology, and function vary between different vascular beds (e.g., arteries, veins, and capillaries). Blood vessels are essential for the delivery of nutrients and oxygen to tissues, as well as for removal of waste products.

Embryoid body blood island