Heparin immobilized on proteins usable for arterial prosthesis coating: growth inhibition of smooth-muscle cells.

Gelatin or a mixture of albumin and gelatin has been proposed for the coating of vascular grafts according to their surface thrombogenicity and biocompatibility, and the possibility of biodegradation. Heparin treatment of hemocompatible surfaces improved the patency of prostheses. In this study, different amounts of heparin were immobilized on these protein gels using a water-soluble carbodiimide [1-ethyl-3-(3-dimethylaminopropyl) carbodiimide].

Prostacyclin secretion by human endothelial cells grown on carbodiimide cross-linked proteins: an assessment of the cytocompatibility of a substratum.

Prostacyclin production by human umbilical vein endothelial cells cultured on carbodiimide cross-linked albumin and/or gelatin was quantified during the exponential growth phase and in confluent cultures as a response to arachidonic acid stimulus. In confluent cultures, basal production of prostacyclin measured by radioimmunoassay of the stable metabolite 6-keto-PGF1 alpha was comparable for both substrates to a control culture. Maximal release of prostacyclin occurred during the first 24 h following cell seeding and these values were significantly higher in media from cultures performed on membranes.

IL-1-induced procoagulant and fibrinolytic activities of human endothelium grown on carbodiimide crosslinked proteins.

We examined the regulation of procoagulant activity and the production of fibrinolytic components by human vascular endothelium grown on coating membranes of gelatin, pure or mixed with albumin, crosslinked by carbodiimide ((G)C, (AG)C) in comparison with plastic culture dishes. Confluent monolayers were stimulated by human recombinant interleukin (IL-1 beta) and responses in terms of tissue factors like procoagulant activity, tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI-1) were followed for up to 72 h. Procoagulant activity of cell extracts displayed similar patterns whatever the substratum tested.

Comparative behaviour of L-929 fibroblastic and human endothelial cells onto crosslinked protein substrates.

Studies were carried out to compare the behaviour of human umbilical vein endothelial cells (HUVEC) and L-929 fibroblastic cells towards proteins crosslinked by glutaraldehyde (GTA) or carbodiimide (CDI) proposed for coating of vascular prostheses. CDI crosslinking of bovine serum albumin used alone, or mixed with gelatin, allowed higher rates of cell growth and DNA synthesis than GTA crosslinking independent of cells. Assessment of the plating efficiency revealed a similar behaviour of both cells towards membranes and reference plastic surface in terms of percentages of bound cells.