Detection of fibronectin on vascular flow surfaces by enzyme-linked immunosorbent assay

Numerous variables are involved in the attachment of endothelial cells to a substrate. Quantifying these factors both on native vessels and on synthetic substrates is important in determining the success of endothelial cell attachment, retention, and growth on these substrates. Fibronectin is an important cell attachment molecule and is likely to be key to the successful attachment of endothelial cells to any substrate. For this reason we have developed an enzyme-linked immunosorbent assay for interrogation of the luminal surface of native and synthetic vessels for the presence of fibronectin. A plexiglass chamber was designed with two blocks, an upper block with wells and a lower supporting block. The chamber was then assembled with a vessel between the two blocks, forming the bottom of the well. This luminal surface was then interrogated by conventional enzyme-linked immunosorbent assay. Native vessels, collagenase-digested vessels, acellular matrices and PTFE preclotted with whole blood were assayed to determine the quantity of fibronectin present. These results were correlated with a bioassay developed to determine the quantity of fibronectin necessary for cell attachment. It was concluded that all of the samples assayed had ample fibronectin for cell attachment and that other factors must be responsible for successful maintenance of a cell monolayer.