Synthesis and characterization of albumin binding surfaces for implantable surfaces

Implanted medical devices are of increasing importance in the practice of medicine and it is estimated that more than 3-million people in the United States have long-term implants like vascular grafts, pacemakers, catheters and joint replacements. Even though most biomedical polymers employed are relatively inert, unreactive, and non-toxic, most implant materials when contacted with blood invoke the activation of blood cells as well as the plasma proteolytic enzyme systems. In order to overcome aforementioned problems, attempts have been made to modify the surface chemistry of the blood-contacting biomaterials so that they become thromboresistant. One potential strategy to address the problem of the chaotic adsorption of proteins to medical devices and surfaces is to create a layer of albumin as a "barrier protein cover", as a thin layer of albumin has been reported to minimize adhesion and aggregation of platelets. By grafting peptides and synthetic ligands, that specifically bind human serum albumin, on an epoxide functionalized surface, we have generated surfaces that exhibit enhanced albumin binding over other serum proteins. We have characterized the surface using infra-red ellipsiometry and quantified protein adsorption via specific ELISA assays and gel electrophoresis.