Endothelial cell reaction on a biological material.

The successful clinical application of materials should involve detailed investigations on interaction between them and tissue with which they will contact. We examined herein the behavior of endothelial cells (ECs) on a collagen material, using histological and immunohistochemical methods. We used isolated human umbilical cord vein cells (HUVECs) identified by means of endothelial-specific antibodies. Cells were seeded in a standard density on a collagen membrane (Lycoll, Resorba, Nuernberg, Germany) and on gelatin-coated, control plastic surfaces, after two passages. These were then maintained for periods of 1, 7, or 14 days. The cells adhered, spread, and proliferated, and within 24 h started forming a subconfluent monolayer. We observed that the cultured cells expressed integrins (alpha5beta1 and alpha(v)beta3) and synthesized fibronectin. After 14 days, we could observe a confluent layer of ECs. We could conclude that the collagen material supported growth and attachment of endothelial cells. In addition, the attachment seemed to be most related to the fibronectin synthesized by the cells and to its highly expressed receptor (the alpha5beta1 integrin); even though this is not the only protein related to this adhesion, we observed that our cultured HUVECs did not synthesize vitronectin.