Thin-film micromesh for medical devices and related methods

Abstract

Thin-film mesh for medical devices, including stent and scaffold devices, and related methods are provided. Micropatterned thin-film mesh, such as thin-film Nitinol (TFN) mesh, may be fabricated via sputter deposition on a micropatterned wafer. The thin-film mesh may include slits to be expanded into pores, and the expanded thin-film mesh used as a cover for a stent device. The stent device may include two stent modules that may be implanted at a bifurcated aneurysm such that one module passes through a medial surface of the other module. The thin-film mesh may include pores with complex, fractal, or fractal-like shapes. The thin-film mesh may be used as a scaffold for a scaffold device. The thin-film scaffold may be placed in a solution including structural protein such as fibrin, seeded with cells, and placed in the body to replace or repair tissue.

What is claimed is: 
     
         1 . A method comprising:
 forming a metallic thin film on a substrate by sputter deposition;   forming fenestrations in the metallic thin film based on micropatterns provided on the substrate;   placing the metallic thin film in a solution to form structural proteins on the metallic thin film.   
     
     
         2 . The method of  claim 1 , further comprising expanding the metallic thin film to open up the fenestrations, such that the metallic thin film has a pore density of between 65 and 1075 pores per mm 2  and a percent area coverage of between 16 and 66%; 
     
     
         3 . The method of  claim 1 , wherein the fenestrations form a fractal-like micropattern. 
     
     
         4 . The method of  claim 1 , further comprising adding one or more small molecules or large molecules to the metallic thin film or the structural proteins configured to achieve a desired therapeutic effect at an anatomic site of interest where the metallic thin film is to be deployed. 
     
     
         5 . The method of  claim 1 , further comprising:
 deep reactive ion etching a micropattern of trenches on a surface of the substrate, the trenches corresponding to the fenestrations of the metallic thin-film;   depositing a lift-off layer on the etched substrate;   depositing a first Nitinol layer over the lift-off layer; and   etching the lift-off layer to form the metallic thin film.   
     
     
         6 . The method of  claim 5 , further comprising:
 depositing a bonding layer on at least one area of the first Nitinol layer;   depositing a sacrificial layer on a remaining area of the first Nitinol layer;   depositing a second Nitinol layer on the bonding layer and the sacrificial layer; and   annealing the first Nitinol layer and the second Nitinol layer with the bonding layer;   wherein the etching further etches the sacrificial layer to form a three-dimensional, metallic thin film micromesh.   
     
     
         7 . The method of  claim 1 , further comprising:
 forming a plurality of metallic thin films;   placing the plurality of metallic thin films in one or more solutions to form structural proteins on the plurality of metallic thin films; and   stacking the plurality of metallic thin films to form a three-dimensional thin-film micromesh structure.   
     
     
         8 . The method of  claim 1 , further comprising:
 forming a plurality of metallic thin films;   forming an inner and an outer thin-film mesh cylinders from the plurality of metallic thin films;   placing the inner and the outer thin-film mesh cylinders in one or more solutions to form structural proteins on the inner and the outer thin-film mesh cylinders; and   enclosing the inner thin-film mesh cylinder in the outer thin-film mesh cylinder to form a multi-layer thin-film mesh cylinder structure.   
     
     
         9 . The method of  claim 1 , further comprising:
 seeding the metallic thin film with cells; and   incubating the metallic thin film to promote cell growth.   
     
     
         10 . The method of  claim 1 , further comprising:
 placing the metallic thin film over a backbone to form a cylindrical tube; and   attaching the metallic thin film to the backbone.