Biocompatible surfaces using methacryloylphosphorylcholine laurylmethacrylate copolymer.

Many materials used in the medical device industry were not originally developed for these applications. In general, these materials elicit adverse biologic responses when in contact with body fluids such as blood, and the mechanisms of the response of blood to an artificial surface are well characterized. Protein adsorption, platelet adhesion, and activation of the coagulation pathway can subsequently lead to thrombus formation with grave clinical consequences in the absence of anticoagulant. However, the use of anticoagulants can result in complications. In recent years various approaches for overcoming these problems by improvement of the biocompatibility of materials have been advocated. One approach is that of biomembrane mimicry, whereby the surface of a material is coated with a derivative of phosphorylcholine (PC). PC is the major lipid head group component found in the outer surface of biologic cell membranes. In this paper, the application of PC coatings to a range of materials is discussed together with characterization of the surfaces using in vitro biocompatibility tests. Studies of fibrinogen and platelet binding have shown significant reductions in adsorption of these components to various PC coated materials relative to uncoated controls. Materials tested, amongst others, include PVC, polyethylene, polycarbonate, and nylon. The stability of the PC coatings has been studied using radiolabeled derivatives. Results using several materials show that physiadsorbed PC coatings are extremely stable, thus making the coatings suitable for use in a wide variety of medical applications. Extensive biologic evaluations to assess the toxicologic profile of PC derivatives and coated devices have also been carried out and in all tests the materials have been shown to be nontoxic, thus making them suitable for human use. Ex vivo animal and human studies performed support the in vitro data.