Thermoplastic fluoropolymer-coated medical devices

Abstract

A medical device provided with at least a partial surface coating of a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether that is free of cross-linking monomers and curing agents. The fluoropolymer coating is preferably an amorphous thermoplastic, is highly inert and biocompatible, has elastomeric characteristics that provide desirable mechanical properties such as good flexibility and durability. These characteristics allow the coating to be considered “functionally transparent” because it withstands mechanical deformations required for the assembly, deployment, expansion, and placement of medical devices, without any adverse effect on the mechanical and biological functionality of the coated device. Further, its inertness, derived from the perfluorocarbon structure, contributes to its functionally transparent nature. The coating can be provided with various liquid or solid additives, can be loaded with large quantities of additives including a wide range of therapeutic agents, and has excellent drug elution characteristics when elutable additives are used. The desirable mechanical characteristics are surprising given the absence of cross-linking monomers and curing agents that would otherwise render such materials inadequately biocompatible. The perfluoroalkylvinylether may be perfluoromethylvinylether, perfluoroethylvinylether or perfluoropropylvinylether.

The invention claimed is:  
     
         1 . An implantable device comprising at least one bendable element provided with a coating of a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether over at least a portion of a surface of the bendable element, wherein said copolymer is free of cross-linking monomers and curing agents, and said coating is substantially free of macroscopic cracks immediately following normal bending of the bendable element.  
     
     
         2 . An implantable device according to  claim 1  wherein said bendable element is an expandable endoluminal element, wherein said coating is substantially free of macroscopic cracks immediately following normal expansion of the expandable endoluminal element.  
     
     
         3 . An implantable device according to  claim 2  wherein said device is a tubular expandable stent having a diameter prior to expansion wherein normal expansion increases the diameter by 50 percent.  
     
     
         4 . An implantable device according to  claim 1  wherein the perfluoroalkylvinylether is perfluoromethylvinylether.  
     
     
         5 . An implantable device according to  claim 1  wherein the perfluoroalkylvinylether is perfluoroethylvinylether.  
     
     
         6 . An implantable device according to  claim 1  wherein the perfluoroalkylvinylether is perfluoropropylvinylether.  
     
     
         7 . An implantable device according to  claim 1  wherein the coating contains an additive.  
     
     
         8 . An implantable device according to  claim 7  wherein the coating contains at least 70 weight percent weight additive.  
     
     
         9 . An implantable device according to  claim 7  wherein the coating contains at least 50 weight percent weight additive.  
     
     
         10 . An implantable device according to  claim 7  wherein the coating contains at least 30 weight percent weight additive.  
     
     
         11 . An implantable device according to  claim 7  wherein the coating contains at least 20 weight percent weight additive.  
     
     
         12 . An implantable device according to  claim 7  wherein the additive comprises a therapeutic agent.  
     
     
         13 . An implantable device according to  claim 12  wherein the amount and rate of release of the therapeutic agent from the implantable device is controlled by adjusting the relative types and/or concentrations of polymers in the copolymer.  
     
     
         14 . An implantable device according to  claim 12  wherein the therapeutic agent comprises rapamycin.  
     
     
         15 . An implantable device according to  claim 12  wherein the therapeutic agent comprises dexamethasone.  
     
     
         16 . An implantable device according to  claim 12  wherein the therapeutic agent comprises heparin.  
     
     
         17 . An implantable device according to  claim 12  wherein the therapeutic agent comprises paclitaxel.  
     
     
         18 . An implantable device according to  claim 12  wherein the therapeutic agent comprises an anti-coagulant.  
     
     
         19 . An implantable device according to  claim 12  wherein the therapeutic agent comprises an anti-microbial.  
     
     
         20 . An implantable device according to  claim 7  wherein the additive comprises a substance that enhances imaging of the implantable device following implantation.  
     
     
         21 . An implantable device according to  claim 7  wherein the additive comprises a substance that enhances visualization of the implantable device.  
     
     
         22 . An implantable device according to  claim 1  wherein the coating may be exposed to a temperature of 330° C. for one hour with a weight loss of less than five percent.  
     
     
         23 . An implantable device according to  claim 1  wherein the copolymer is an amorphous thermoplastic.  
     
     
         24 . A device comprising a medical device provided with a coating over at least a portion of a surface of the medical device, said coating comprising a thermoplastic copolymer of tetrafluoroethylene and perfluoropropylvinylether, said copolymer being free of cross-linking monomers and curing agents.  
     
     
         25 . A device according to  claim 24  wherein said medical device is an implantable medical device.  
     
     
         26 . A device according to  claim 24  wherein said medical device comprises an expandable stent.  
     
     
         27 . A device according to  claim 24  wherein said coating contains a therapeutic agent.  
     
     
         28 . A device according to  claim 24  wherein the copolymer is an amorphous thermoplastic.  
     
     
         29 . A device according to  claim 24  wherein said coating contains an additive.  
     
     
         30 . A device comprising a medical device provided with a coating over at least a portion of a surface of the medical device, said coating comprising a thermoplastic copolymer of tetrafluoroethylene and perfluoroethylvinylether, said copolymer being free of cross-linking monomers and curing agents.  
     
     
         31 . A device according to  claim 30  wherein said medical device is an implantable medical device.  
     
     
         32 . A device according to  claim 30  wherein said medical device comprises an expandable stent.  
     
     
         33 . A device according to  claim 30  wherein said coating contains a therapeutic agent.  
     
     
         34 . An implantable device according to  claim 30  wherein the copolymer is an amorphous thermoplastic.  
     
     
         35 . A device according to  claim 30  wherein said coating contains an additive.  
     
     
         36 . An implantable device comprising a first form expandable to a second form different from the first form, said device having at least two expandable endoluminal elements in adjacent relationship with an open interstice between the two expandable endoluminal elements, said expandable endoluminal elements provided with a coating over at least a portion of a surface of the expandable endoluminal elements such that said coating covers the open interstice between the adjacent expandable endoluminal elements rendering it no longer open, said coating comprising a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether, wherein said coating continues to cover the interstice between the adjacent elements immediately following normal expansion of the expandable endoluminal elements to the second form.  
     
     
         37 . An implantable device according to  claim 36  wherein said copolymer is free of cross-linking monomers and curing agents.  
     
     
         38 . An implantable device according to  claim 36  wherein said endoluminal elements comprise an expandable stent.  
     
     
         39 . An implantable device according to  claim 38  wherein during normal expansion said stent has a diameter that is increased 50 percent.  
     
     
         40 . An implantable device according to  claim 39  wherein said stent comprises a balloon expandable stent.  
     
     
         41 . An implantable device according to  claim 39  wherein said stent comprises a self-expanding stent.  
     
     
         42 . An implantable device according to  claim 38  wherein said stent comprises a stainless steel stent.  
     
     
         43 . An implantable device according to  claim 38  wherein said stent comprises a nitinol stent.  
     
     
         44 . An implantable device according to  claim 36  wherein the copolymer is an amorphous thermoplastic.  
     
     
         45 . An implantable device according to  claim 36  wherein the coating contains a therapeutic agent.  
     
     
         46 . An implantable device according to  claim 36  wherein the second form is larger than the first form.  
     
     
         47 . An implantable device comprising a device having expandable endoluminal elements in adjacent relationship with an open interstice between adjacent expandable endoluminal elements, said expandable endoluminal elements provided with a covering over at least one open interstice rendering it no longer open, wherein at least a portion of said covering and at least a portion of said endoluminal elements are provided with a coating comprising a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether.  
     
     
         48 . An implantable device according to  claim 47  wherein said coating contains a therapeutic agent capable of eluting from the coating over time following implantation in a body conduit.  
     
     
         49 . An implantable device according to  claim 47  wherein said device is a stent-graft having a small, compacted form expandable to a larger form.  
     
     
         50 . An implantable device according to  claim 49  wherein said coating contains a therapeutic agent that elutes from the coating over time following implantation in a body conduit.  
     
     
         51 . An implantable device according to  claim 49  wherein said covering comprises polytetrafluoroethylene.  
     
     
         52 . An implantable device according to  claim 1  wherein said covering comprises polyethylene terephthalate.  
     
     
         53 . An implantable device according to  claim 51  wherein said coating comprises a copolymer of tetrafluoroethylene and perfluoromethylvinylether.  
     
     
         54 . An implantable device according to  claim 51  wherein said coating contains a therapeutic agent that elutes from the coating over time following implantation in a body conduit.  
     
     
         55 . An implantable device according to  claim 47  wherein said coating comprises a copolymer of tetrafluoroethylene and perfluoromethylvinylether.  
     
     
         56 . An implantable device according to  claim 47  wherein said coating comprises a copolymer of tetrafluoroethylene and perfluoroethylvinylether.  
     
     
         57 . An implantable device according to  claim 47  wherein said coating comprises a copolymer of tetrafluoroethylene and perfluoropropylvinylether.  
     
     
         58 . An implantable device according to  claim 49  wherein the larger expanded form of said stent-graft has an outside diameter 50 percent larger than said small, compacted form.  
     
     
         59 . An implantable device according to  claim 47  wherein the copolymer is an amorphous thermoplastic.  
     
     
         60 . An article comprising a medical device provided with a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether coating over at least a portion of a surface of the medical device, said coating containing a therapeutic agent, said therapeutic agent capable of eluting out of said coating at a rate following implantation of said article into a living body, wherein following puncture of said article with a surgical tool followed by removal of said tool, said rate is substantially increased.  
     
     
         61 . An implantable device according to  claim 60  wherein the copolymer is an amorphous thermoplastic.  
     
     
         62 . An article comprising a medical device provided with a coating over at least a portion of a surface of the medical device, said coating comprising a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether, said coating containing a therapeutic agent that, following implantation of the device into a body conduit, will continue to elute out of the coating over a period of 30 days or more.  
     
     
         63 . An article according to  claim 62  wherein the therapeutic agent will continue to elute out of the coating over a period of 45 days or more.  
     
     
         64 . An article according to  claim 62  wherein the therapeutic agent will continue to elute out of the coating over a period of 60 days or more.  
     
     
         65 . An article according to  claim 62  wherein said copolymer is free of cross-linking monomers and curing agents.  
     
     
         66 . An article according to  claim 65  wherein the therapeutic agent will continue to elute out of the coating over a period of 24 hours or more.  
     
     
         67 . An article according to  claim 65  wherein the therapeutic agent will continue to elute out of the coating over a period of 3 days or more.  
     
     
         68 . An article according to  claim 65  wherein the therapeutic agent will continue to elute out of the coating over a period of 10 days or more.  
     
     
         69 . An article according to  claim 65  wherein the therapeutic agent will continue to elute out of the coating over a period of 30 days or more.  
     
     
         70 . An article according to  claim 62  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoropropylvinylether.  
     
     
         71 . An article according to  claim 62  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoroethylvinylether.  
     
     
         72 . An article according to  claim 62  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoromethylvinylether.  
     
     
         73 . An article according to  claim 62  wherein said copolymer is an amorphous thermoplastic.  
     
     
         74 . An article according to  claim 62  comprising an expandable stent.  
     
     
         75 . An article according to  claim 62  comprising an expandable stent-graft.  
     
     
         76 . A device comprising a medical device provided with a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether coating over at least a portion of a surface of the medical device, said coating being attached directly to a portion of the surface of the medical device in the absence of a surface treatment of the portion of the medical device.  
     
     
         77 . A device according to  claim 76  wherein the coating is applied with the use of a primer.  
     
     
         78 . A device according to  claim 76  wherein said copolymer is free of cross-linking monomers and curing agents.  
     
     
         79 . An article according to  claim 76  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoropropylvinylether.  
     
     
         80 . An article according to  claim 76  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoroethylvinylether.  
     
     
         81 . An article according to  claim 76  wherein said copolymer is a thermoplastic copolymer of tetrafluoroethylene and perfluoromethylvinylether.  
     
     
         82 . An article according to  claim 76  wherein said coating is an amorphous thermoplastic.  
     
     
         83 . An article according to  claim 77  wherein said coating is an amorphous thermoplastic.  
     
     
         84 . An article according to  claim 76  comprising an expandable stent.  
     
     
         85 . An article according to  claim 76  comprising an expandable stent-graft.  
     
     
         86 . An article according to  claim 76  wherein said coating contains a therapeutic agent.  
     
     
         87 . An article according to  claim 76  wherein said coating contains an additive.  
     
     
         88 . An implantable device comprising at least one expandable endoluminal element provided with coating of a thermoplastic copolymer of tetrafluoroethylene and perfluoroalkylvinylether over at least a portion of a surface of the expandable endoluminal element, wherein said copolymer is free of cross-linking monomers and curing agents, and said coating is substantially free of macroscopic cracks immediately following normal expansion of the expandable endoluminal element.  
     
     
         89 . An implantable device according to  claim 88  wherein said device is a tubular expandable stent having a diameter prior to expansion wherein normal expansion increases the diameter by 50 percent.  
     
     
         90 . An implantable device according to  claim 88  wherein the perfluoroalkylvinylether is perfluoromethylvinylether.  
     
     
         91 . An implantable device according to  claim 88  wherein the perfluoroalkylvinylether is perfluoroethylvinylether.  
     
     
         92 . An implantable device according to  claim 88  wherein the perfluoroalkylvinylether is perfluoropropylvinylether.  
     
     
         93 . An implantable device according to  claim 88  wherein the coating contains an additive.  
     
     
         94 . An implantable device according to  claim 93  wherein the coating contains at least 70 weight percent weight additive.  
     
     
         95 . An implantable device according to  claim 93  wherein the coating contains at least 50 weight percent weight additive.  
     
     
         96 . An implantable device according to  claim 93  wherein the coating contains at least 30 weight percent weight additive.  
     
     
         97 . An implantable device according to  claim 93  wherein the coating contains at least 20 weight percent weight additive.  
     
     
         98 . An implantable device according to  claim 93  wherein the additive comprises a therapeutic agent.  
     
     
         99 . An implantable device according to  claim 98  wherein the therapeutic agent comprises rapamycin.  
     
     
         100 . An implantable device according to  claim 98  wherein the therapeutic agent comprises dexamethasone.  
     
     
         101 . An implantable device according to  claim 98  wherein the therapeutic agent comprises heparin.  
     
     
         102 . An implantable device according to  claim 98  wherein the therapeutic agent comprises paclitaxel.  
     
     
         103 . An implantable device according to  claim 12  wherein the therapeutic agent comprises an anti-coagulant.  
     
     
         104 . An implantable device according to  claim 12  wherein the therapeutic agent comprises an anti-microbial.  
     
     
         105 . An implantable device according to  claim 93  wherein the additive comprises a substance that enhances imaging of the implantable device following implantation.  
     
     
         106 . An implantable device according to  claim 93  wherein the additive comprises a substance that enhances visualization of the implantable device.  
     
     
         107 . An implantable device according to  claim 88  wherein the coating may be exposed to a temperature of 330° C. for one hour with a weight loss of less than five percent.  
     
     
         108 . An implantable device according to  claim 88  wherein the copolymer is an amorphous thermoplastic.