EXPERIMENTAL-STUDY OF THE ANTITHROMBOGENIC BEHAVIOR OF DACRON VASCULAR GRAFTS COATED WITH HYDROPHILIC ACRYLIC COPOLYMERS BEARING SALICYLIC-ACID RESIDUES

The objective of the present work was study of the behavior of active coatings of hydrophilic acrylic polymers bearing salicylic acid residu es linked covalently to the macromolecular chains, after their applica tion to woven and knitted Dacron vascular grafts. In vitro tests were carried out under dynamic flow conditions using equipment especially d esigned to reproduce physiologic conditions, to determine the retentio n of the coating using a saline solution. Ex vivo tests were carried o ut in an extracorporeal circuit using the dog as an animal model. The study of the deposition of platelets was followed by labeling of autol ogous platelets with (111)Inoxine, as well as by analysis of the surfa ces of the prostheses by scanning electron microscopy. An application of thin coatings of hydrophilic acrylic copolymers improves the antith rombogenicity of the vascular grafts with respect to the uncoated pros thesis. The presence of relatively small amounts of units bearing sali cylic acid residues in the copolymer chains (5-20 wt %) gives good res ults when they are applied to woven and knitten Dacron meshes which ha ve been quantified by analysis of the percentage of radiotracer on the surface of the vascular grafts tested in ex vivo experiments. The sal icylic acid residues are released slowly to the medium by hydrolysis o f the reversible covalent bonds of this compound to the acrylic macrom olecular chains, which provides an additional antiaggregating effect f or platelets. The polymeric coating forms a thin active film which imp roves the antithrombogenic properties of the surface of woven or knitt ed Dacron vascular grafts in ex vivo experiments. (C) 1996 John Wiley & Sons, Inc.