ABSTRACT
To observe the morphological features of endothelial cells and cardiac explants cultured in two- or three-dimensional culture systems, several three-dimensional collagen type I culture systems, such as the in gel, on gel, sandwich model, and the microscope slide model, were used to examine the growth patterns of the cells and explants from heart by using immunofluorescence staining and microscopic observation in the presence or absence of vascular endothelial growth factor (VEGF). In two-dimensional cultures the primary cardiac endothelial cells arrayed into a cobblestone-like structure. When cultured in three-dimensional matrix, the cells were elongated and migrated into the gel, with a phenotype similar to that in the process of angiogenesis and vasculogenesis in vivo. VEGF promoted the process of the endothelial cells transforming into tube-like structure. Cardiac explants grew well in the collagen gel. Adjacent explants were connected to each other by the migrating cells with the occurrence of autorhythmic beating of the explants. Thin-layer collagen gel, microscope slide chamber and aorta-strip model were also tested and proved to be good tools for vasculogenesis or angiogenesis studies. Three-dimensional culture systems enable the endothelial cells to proliferate, migrate, and anchor to three-dimensional vascular structures, showing advantages for observing the feature of angiogenesis. Different three-dimensional culture models may be used for variable research purposes.