Comparative study of tube assembly in three-dimensional collagen matrix and on Matrigel coats

This study compares phenotypic changes of human umbilical endothelial vein cells cultured in three-dimensional collagen matrixes in the presence of basic fibroblast growth factor or on Matrigel coats. Under both conditions, endothelial cells rapidly assembled into an irregular network of tubular structures with a high frequency of intercellular or lumen-like spaces. Tubular structures were characterized and compared by phase-contrast, confocal and electron microscopy. The dominant mechanism of lumen-like formation was highly model-dependent. Ultrastructural analyses of capillary-like structures and the mechanism of lumen-like formation indicated that the in vivo angiogenesis was better reproduced in the collagen model.