Metal alloy for medical devices and implants

Abstract

The present invention relates to a medical device or implant made at least in part of a high strength, low modulus metal alloy comprising Niobium, Tantalum, and at least one element selected from the group consisting of Zirconium, Tungsten, and Molybdenum. The medical devices according to the present invention provide superior characteristics with regard to bio-compatibility, radio-opacity and MRI compatibility.

What is claimed is: 
     
         1 . A stent, comprising:
 a generally tubular member having a wall, the tubular member being constructed of a tantalum based alloy having a composition including,   about 10 weight percent Niobium;   about 7.5 weight percent of Tungsten;   up to 5 weight percent of at least one additional alloying element; and   a balance of Tantalum.   
     
     
         2 . The stent according to  claim 1 , wherein the alloy is cold-worked to increase the strength thereof. 
     
     
         3 . The stent according to  claim 1 , wherein the stent further includes a coating disposed upon a surface of the tubular member. 
     
     
         4 . The stent according to  claim 1 , wherein the tubular member exhibits a reduced wall thickness that provides a minimalized diameter in the compressed state. 
     
     
         5 . The stent according to  claim 11 , wherein the reduced wall thickness further reduces turbulence of fluid flow through a lumen of the tubular member. 
     
     
         6 . The stent according to  claim 1 , wherein the alloy exhibits a substantially uniform beta structure. 
     
     
         7 . A stent, comprising:
 a generally tubular member having a wall, the tubular member configured to be expandable from a radially compressed state to an expanded state, the tubular member being constructed of a tantalum based alloy having a composition including,   about 10 weight percent Niobium;   about 7.5 weight percent of Tungsten;   up to 5 weight percent of at least one additional alloying element; and   a balance of Tantalum.   
     
     
         8 . The stent according to  claim 7 , wherein the at least one additional alloying element is selected from the group consisting of Hafnium, Rhenium, and a Lathanide element. 
     
     
         9 . The stent according to  claim 7 , wherein the alloy is cold-worked to increase the strength thereof. 
     
     
         10 . The stent according to  claim 7 , wherein the stent further includes a coating disposed upon a surface of the tubular member. 
     
     
         11 . The stent according to  claim 10 , wherein the coating is a polymer. 
     
     
         12 . The stent according to  claim 11 , wherein the coating is a blend of polymers. 
     
     
         13 . The stent according to  claim 10 , wherein the coating is selected from the group consisting of biomolecules, peptides, proteins, lipids, carbohydrates and nucleic acids. 
     
     
         14 . The stent according to  claim 10 , wherein the coating includes stem cells. 
     
     
         15 . The stent according to  claim 10 , wherein the coating is a bioactive substance. 
     
     
         16 . The stent according to  claim 15 , wherein the bioactive substance is chosen from the group consisting of antibiotics, growth factors, anti-inflammatory agents and anti-thrombogenic agents. 
     
     
         17 . The stent according to  claim 7 , wherein the tubular member exhibits a reduced wall thickness that provides a minimalized diameter in the compressed state. 
     
     
         18 . The stent according to  claim 17 , wherein the reduced wall thickness further reduces turbulence of fluid flow through a lumen of the tubular member. 
     
     
         19 . The stent according to  claim 7 , wherein the alloy exhibits a substantially uniform beta structure. 
     
     
         20 . A stent, comprising:
 a generally tubular member having a wall, the tubular member configured to be expandable from a radially compressed state to an expanded state, the tubular member being constructed of an alloy having a composition including,   about 5 to about 25 weight percent Niobium;   about 0.1 to about 15 weight percent of at least one element selected from the group consisting of Tungsten and Molybdenum;   up to 5 weight percent of at least one element selected from the group consisting of Hafnium, Rhenium, and a Lathanide element; and   about 55 to about 94.9 weight percent Tantalum.   
     
     
         21 . The stent according to  claim 20 , wherein the composition of the alloy includes about 10 weight percent Niobium, about 2.5 weight percent Tungsten, and the balance being Tantalum. 
     
     
         22 . The stent according to  claim 20 , wherein the composition of the alloy includes about 10 weight percent Niobium, about 7.5 weight percent Tungsten, and the balance being Tantalum. 
     
     
         23 . The stent according to  claim 20 , wherein the composition of the alloy includes about 0.1 to about 15 weight percent Tungsten. 
     
     
         24 . The stent according to  claim 20 , wherein the composition of the alloy includes about 10 weight percent Niobium. 
     
     
         25 . The stent according to  claim 20 , wherein the alloy is cold-worked to increase the strength thereof. 
     
     
         26 . The stent according to  claim 20 , wherein the stent further includes a coating disposed upon a surface of the tubular member. 
     
     
         27 . The stent according to  claim 26 , wherein the coating is a polymer. 
     
     
         28 . The stent according to  claim 27 , wherein the coating is a blend of polymers. 
     
     
         29 . The stent according to  claim 28 , wherein the coating is selected from the group consisting of biomolecules, peptides, proteins, lipids, carbohydrates and nucleic acids. 
     
     
         30 . The stent according to  claim 28 , wherein the coating includes stem cells. 
     
     
         31 . The stent according to  claim 28 , wherein the coating is a bioactive substance. 
     
     
         32 . The stent according to  claim 31 , wherein the bioactive substance is chosen from the group consisting of antibiotics, growth factors, anti-inflammatory agents and anti-thrombogenic agents. 
     
     
         33 . The stent according to  claim 20 , wherein the tubular member exhibits a reduced wall thickness that provides a minimalized diameter in the compressed state. 
     
     
         34 . The stent according to  claim 33 , wherein the reduced wall thickness further reduces turbulence of fluid flow through a lumen of the tubular member. 
     
     
         35 . The stent according to  claim 20 , wherein the alloy exhibits a substantially uniform beta structure. 
     
     
         36 . A stent, comprising:
 a generally tubular member having a wall, the tubular member configured to be expandable from a radially compressed state to an expanded state, the tubular member being constructed of an alloy having a composition including,
 about 5 to about 25 weight percent Niobium; 
 about 0.1 to about 15 weight percent of at least one element selected from the group consisting of Tungsten and Molybdenum; and 
 about 60 to about 94.9 weight percent Tantalum. 
   
     
     
         37 . The stent according to claim  58 , wherein the composition of the alloy includes about 10 weight percent Niobium, about 7.5 weight percent Tungsten, and the balance being Tantalum. 
     
     
         38 . The stent according to claim  58 , wherein the alloy is cold-worked to increase the strength thereof. 
     
     
         39 . The stent according to claim  58 , wherein the alloy exhibits a substantially uniform beta structure. 
     
     
         40 . A stent, comprising:
 a generally tubular member having a wall, the tubular member configured to be expandable from a radially compressed state to an expanded state, the tubular member being constructed of an alloy having a composition including,
 about 10 weight percent Niobium; 
 about 0.1 to about 15 weight percent Tungsten; and 
 about 75 to about 89.9 weight percent Tantalum. 
   
     
     
         41 . The stent according to claim  62 , wherein the composition of the alloy includes about 7.5 weight percent Tungsten.