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]. The results showed a coupling of heparin with gelatin and/or albumin at the surface of the gels, stable for as long as 1 month. From 0.20 to 3.60 microg x cm(-2), heparin could be immobilized. The antiproliferative activity of immobilized heparin was controlled toward bovine smooth-muscle cells grown on these gels. Cell growth inhibition was dose dependent, but the percentages of inhibition were lower at day 8 than at day 4 at any heparin concentration used under experimental conditions. Referring to heparin in solution, immobilized heparin displayed an antiproliferative activity that improved the potential interest for coating.