Medical device chemically modified by plasma polymerization

Abstract

Medical devices, and particularly intracorporeal devices for therapeutic or diagnostic uses, having a component chemically modified by plasma polymerization. The medical device comprises a substrate with a plasma polymerized functionality bonded to a surface of at least a section thereof. The plasma polymerized film on a first component of the medical device allows for bonding an agent or a second component to the first component. In one embodiment, the plasma polymerized film facilitates fusion or adhesive bonding of a first component to a second component formed of a material which is dissimilar to, incompatible with, or otherwise not readily bondable to the substrate material of the first component. In another embodiment, a bioactive agent is bonded to the plasma polymerized film on the component, for presenting or delivering the bioactive agent within a body lumen of the patient.

1 - 22 . (canceled) 
     
     
         23 . A method of treating a surface of at least a section of a medical device, comprising exposing at least a section the medical device formed of a polymeric material having a node and fibril microstructure to a plasma to deposit a plasma polymerized functionality on the section of the medical device. 
     
     
         24 . The method of  claim 23  wherein the polymeric material of the section of the medical device is expanded polytetrafluoroethylene, and depositing the functionality on the section of the medical device comprises exposing the section to a plasma without decomposing the polymeric material of the section of the medical device. 
     
     
         25 . The method of  claim 23  wherein depositing the functionality on the section of the medical device comprises exposing the section to an acrylic acid plasma to form a carboxylate plasma polymerized film thereon. 
     
     
         26 . The method of  claim 25  including providing carbon dioxide in the acrylic acid plasma to limit a rate of decarboxylation from the section of the medical device. 
     
     
         27 . The method of  claim 23  including bonding an agent selected from the group consisting of a bioactive agent and an adhesive to at least a portion of the section of the medical device having the plasma polymerized functionality. 
     
     
         28 . A method of making a medical device, comprising
 a) exposing at least a section of a first component formed at least in part of a first polymeric material to a plasma to deposit a plasma polymerized functionality on the section of the first component of the device; and   b) bonding a second component formed of a second polymeric material different from the first polymeric material to the section of the first component having the plasma polymerized functionality thereon.   
     
     
         29 . The method of  claim 28  wherein the plasma is applied at a high pressure to chemically modify an inner surface of the first component. 
     
     
         30 . The method of  claim 28  wherein the plasma polymerized functionality is selected from the group consisting of carboxylate, amine, and sulfate, and the plasma polymerized functionality is a film formed with a thickness of about 10 nm to about 150 nm. 
     
     
         31 . The method of  claim 28  wherein the plasma polymerized functionality is selected from the group consisting of a carboxylate, an amine, and a sulfate, and (b) comprises fusion bonding the first component to the second component. 
     
     
         32 . The method of  claim 28  wherein the second polymeric material is incompatible with the first polymeric material, and (b) comprises fusion bonding the first component to the second component. 
     
     
         33 . A method of making a medical device, comprising
 a) exposing at least a section of a substrate of the medical device formed at least in part of a first polymeric material to an acrylic acid plasma, to deposit a plasma polymerized carboxylate functionality on the section of the medical device substrate; and   b) bonding a material different from the first polymeric material to the section of the substrate having the plasma polymerized functionality deposited thereon.   
     
     
         34 . The method of  claim 33  wherein b) comprises fusion or adhesively bonding the material to the substrate. 
     
     
         35 . The method of  claim 33  including generating the acrylic acid plasma by passing argon enriched in acrylic acid monomer through a radio frequency transducer. 
     
     
         36 . The method of  claim 35  wherein carbon dioxide is included with the argon, to limit the rate of decarboxylation from the surface of the substrate having the plasma polymerized and deposited carboxylate functionality. 
     
     
         37 . The method of  claim 33  including minimizing the degree of crosslinking in the plasma polymerized and deposited carboxylate functionality to less than about 5%. 
     
     
         38 . The method of  claim 33  wherein the substrate is exposed to the acrylic acid plasma for about 3 minutes or more to form a plasma polymerized and deposited film having a thickness of about 10 to about 150 nm and having a surface with the same composition as a bulk of the film. 
     
     
         39 . The method of  claim 33  including, before a), treating the substrate with an argon plasma to prepare a surface of the substrate. 
     
     
         40 . The method of  claim 33  wherein following exposure to the acrylic acid plasma, the plasma field is purged with argon under no radio frequency power to allow surface free-radicals to recombine before exposure to atmospheric oxygen.