The newly formed vessels showed characteristics of natural blood vessel as they occur in the in vivo angiogenesis. Certain morphological structures play a role, for instance a directional spread of certain leading cells, characteristic small thread-like appendages at the tips, as well as so-called "stalk cells" which exhibiting a apical-basal polarity.

With the model the scientists are able to investigate mechanisms that lead to neovascularization. They found that antagonists inhibiting the VEGF receptor (vascular endothelial groth factor receptor) does not necessarily lead to the prevention of vessel formation. The agonist bindung normally to the VEGF receptor is an important signaling molecule that plays an important role in the control process of both vasculogenesis and angiogenesis. It was found that the vessels can switch between VEGF-dependent and VEGF-independent angiogenesis. In this process an important function has the sphingosine-1-phosphate.

The findings are also relevant for the study of therapeutics in the tumor treatment.

The researchers were able to show that their three-dimensional model is able to answer important questions in basic research, namely the mechanisms of neovascularization.

More  information:
Nguyen, D.-H. T., Stapleton, S. C., Yang, M. T., Cha, S. S., Choi, C. K., Galie, P. A. & Chen, C. S. (2013): Biomimetic model to reconstitute angiogenic sprouting morphogenesis in vitro. PNAS 110/17: 6712-6717.