In vitro matrigel angiogenesis assays.

A variety of in vivo and in vitro methods have been used to study angiogenesis, the process of blood vessel formation. Two widely accepted but technically difficult assays include the cornea implant assay and the chick chorioallantoic membrane assay. The cornea assay requires special equipment and a skilled person to implant beads containing the test compound in the eyes of animals; only a small number of samples can be tested due to cost and time. The chorioallantoic membrane assay requires a large number of samples on account of the variability of the system and its difficulty in quantitation. In our laboratory, we have developed a quick and highly reliable method for testing numerous compounds for angiogenic and/or antiangiogenic activity. The method is based on the differentiation of ECs on a basement membrane matrix, Matrigel, derived from the Engelbreth-Holm-Swarm tumor (1). ECs from human umbilical cords as well as from other sources differentiate and form capillary-like structures on Matrigel in the presence of 10% bovine calf serum (BCS) and 0.1 mg/mL of endothelial cell growth supplement (ECGS) (2), which is a mixture of both acidic and basic fibroblast growth factor (Fig. 1, Panel C). The formation of tube-like vessels under these conditions can be used to assess compounds that either inhibit or stimulate angiogenesis.