Surface functionalization by RF plasma treatment of polymers for immobilization of bioactive-molecules

A method of functionalizing polymer surfaces of long small diameter tubes, using a water-oxygen RF plasma, is described. The objective was to introduce appropriate functional groups suitable for covalently binding bioactive agents, heparin in particular, through spacer molecules. A new means by which this can be accomplished on the inside surfaces of a long tube is also described. The heparin immobilized surface is nonthrombogenic and this technique can be used to bind heparin to various blood contacting medical devices. The heparinized surfaces were analyzed by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SSIMS), before and after extraction in phosphate buffered saline and 4 M guanidine, to confirm the covalent binding of heparin.