Implants and methdos for manufacturing same

Abstract

Implantable prosthesis, components of prosthesis, and methods of making same are provided. The methods generally include the steps of providing an implant shell, applying a curable fluid composition to the shell to form a coating thereon and applying a particulate component to the composition. The composition is a mixture, for example, an emulsion, containing a silicone-based elastomer dispersion and droplets of a suspended leachable agent. After the elastomer is stabilized and cured, the particulate component and leachable agent are removed, resulting in an implantable member having a porous, open-cell surface texture designed to be effective in reducing incidence of capsular formation or contraction.

1 . An implantable member having an external surface at least a portion of which is an open-cell porous structure, the member made by the method comprising the steps of:
 (a) providing an implantable shell;   (b) applying a curable fluid composition to the shell, the composition comprising a mixture containing an elastomer component, a leachable agent and a solvent component;   (c) applying a layer of particles to the composition;   (d) allowing the composition to stabilize; and   (e) removing the particles and the leachable agent from the stabilized composition to form a composite material having an external surface at least a portion of which is an open-cell porous structure.   
     
     
         2 . The member of  claim 1  wherein the implantable shell is a shell for a breast implant. 
     
     
         3 . The member of  claim 1  wherein the leachable agent is a water soluble polymer. 
     
     
         4 . The member of  claim 1  wherein the leachable agent is an agent selected from the group of agents consisting of polyvinyl alcohol, polyethylene glycol, polyacrylic acid; polymethacrylate, poly-lactide, polyglycolide, polycaprolactone, polydioxanone, derivatives thereof, blends thereof, copolymers thereof, terpolymers thereof, and combinations thereof. 
     
     
         5 . The member of  claim 1  wherein the solvent component includes a solvent selected from the group consisting of xylene, pentane, hexane, dichloromethane (DCM), dimethyl sulfoxide, dioxane, NMP, DMAc, and combinations thereof. 
     
     
         6 . The member of  claim 1  wherein the mixture is an emulsion. 
     
     
         7 . The member of  claim 1  wherein the particles comprise a material selected from the group of materials consisting of sodium chloride, barium sulfate, potassium nitrate, sodium carbonate. 
     
     
         8 . The member of  claim 1  wherein the particles are substantially round. 
     
     
         9 . The member of  claim 1  wherein the leachable agent is in the form of droplets having diameters in a range of between about 50 microns to about 400 microns. 
     
     
         10 . The member of  claim 9  wherein the particles have an average particle size in a range of between about 100 microns to about 900 microns. 
     
     
         11 . The member of  claim 1  wherein the particles have an average particle size in a range of between about 100 microns to about 900 microns. 
     
     
         12 . The member of  claim 1  further comprising the step of repeating steps (b) and (c) prior to the step of removing, to form a layered structure. 
     
     
         13 . The member of  claim 1  wherein the step of removing comprises contacting the stabilized composition with a solvent for the particles and the leachable agent. 
     
     
         14 . An implantable composite member having an external surface at least a portion of which is an open-cell porous structure, the member made by the method comprising the steps of:
 (a) providing an implantable shell;   (b) applying a first layer of a curable fluid composition to the shell, the composition comprising a mixture containing an elastomer component, a leachable agent and a solvent component;   (c) applying a first layer of particles to the composition;   (d) applying a second layer of the composition to the first layer of particles;   (e) applying a second layer of particles to the second layer of the composition;   (f) allowing the composition to stabilize; and   (g) removing the particles and the leachable agent from the stabilized composition to form a composite material having an external surface at least a portion of which is an open-cell porous structure.   
     
     
         15 . The member of  claim 14  wherein the first layer of particles comprises relatively small particles and the second layer of particles comprises relatively large particles. 
     
     
         16 . An article suitable for use in as a laminate for an implant, the article comprising:
 a flexible sheet made by the process of:
 (a) applying a particulate component and a curable fluid composition to a mold surface, the fluid composition comprising a mixture containing an elastomer component, a leachable agent and a solvent component; 
 (b) allowing the fluid composition component to stabilize; and 
 (c) removing at least one of the particulate component and the leachable agent from the stabilized composition to form a sheet having an external surface at least a portion of which is an open-cell porous structure; and 
 (d) removing the sheet from the mold surface. 
   
     
     
         17 . An article comprising:
 a sheet suitable for use as a laminate on an implantable object to enhance tissue adhesion or ingrowth when the implantable object is implanted in a patient;   the sheet made by a process comprising the steps of:
 applying a fluid/particulate mixture to a substrate or mold surface, the fluid/particulate mixture comprising a particulate component and a curable fluid component, the curable fluid component containing an elastomer component, a leachable agent and a solvent component; 
 allowing the fluid/particulate mixture to stabilize; and 
 removing the sheet from the substrate or mold surface. 
   
     
     
         18 . The article of  claim 17  further comprising the step of removing at least one of the particulate component and the leachable agent from the stabilized fluid/particulate mixture to form a porous sheet after the step of allowing the fluid/particulate mixture to stabilize. 
     
     
         19 . The article of  claim 18  wherein the step of removing at least one of the particulate component and leachable agent is performed prior to the step of removing the sheet from the substrate of mold surface. 
     
     
         20 . The article of  claim 17  wherein the sheet is a layered sheet and the process further comprises the step of repeating the applying step prior to the step of removing the sheet from the substrate or mold surface.