Apparatus and methods for controlled substance delivery from implanted prostheses

Abstract

The present invention provides improved stents and other prostheses for delivering substances to vascular and other luminal and intracorporeal environments. In particular, the present invention provides luminal prostheses which allow for a programmed and controlled substance delivery protocols for a variety of purposes. The prostheses comprise a scaffold which is implantable within a body lumen and a substance reservoir present over at least a portion of the scaffold. Usually, a rate-controlling element will be formed over the substance-containing reservoir to provide for a number of different substance release characteristics.

1 . A device for intracorporeal use within a patient's body, comprising: 
 an implantable scaffold;    at least one source of at least one therapeutic capable agent associated with the scaffold and configured to release the therapeutic capable agent within the patient's body at a controlled rate; and    a rate-controlling element layer covering at least a portion of the source and including at least one therapeutic capable agent and providing for an initial relatively more rapid release of the at least one therapeutic capable agent therapeutic from the rate-controlling element layer as well as a sustained, controlled release of the at least one therapeutic capable agent from the source.    
     
     
         2 . A device as in  claim 1  wherein the device comprises a stent.  
     
     
         3 . A device as in  claim 2  wherein the stent comprises metallic material.  
     
     
         4 . A device as in  claim 2  wherein the stent comprises polymeric material.  
     
     
         5 . A device as in  claim 4  wherein the stent comprises a degradable material.  
     
     
         6 . A device as in  claim 4  wherein the stent comprises a non-degradable material.  
     
     
         7 . A device as in  claim 2  wherein the device is balloon-expandable.  
     
     
         8 . A device as in  claim 2  wherein the device is self-expandable.  
     
     
         9 . A device for intracorporeal use within a patient's body, comprising: 
 an implantable scaffold;    at least one source of at least one therapeutic capable agent associated with the scaffold; and    a rate-controlling element disposed adjacent at least a portion of the source and being configured to control the release of the therapeutic capable agent in the patient's body at an initial rate and at a subsequent rate relatively slower than the initial rate.    
     
     
         10 . A device as in  claim 1  or  9  wherein the rate-controlling element covers the source.  
     
     
         11 . A device as in  claim 1  or  9  wherein the scaffold comprises a tissue facing and a luminal facing surface.  
     
     
         12 . A device as in claims  1  or  9  wherein the rate-controlling element is formed from a nonporous material.  
     
     
         13 . A device as in  claim 12  wherein the porosity of the rate-controlling element changes upon implanting in the patient's body.  
     
     
         14 . A device as in  claim 12  wherein the rate-controlling element comprises a parylene polymer or copolymer.  
     
     
         15 . A device as in  claim 12  wherein the rate-controlling element becomes at least partially porous upon expansion of the scaffold.  
     
     
         16 . A device as in  claim 1  or  9  wherein the rate-controlling element is formed from a porous material.  
     
     
         17 . A device as in  claim 16  wherein the parylene comprises parylene C.  
     
     
         18 . A device as in  claim 1  or  9  wherein a rate of release of the therapeutic capable agent from the device in an unexpanded state in the patient's body is different than that in an expanded state.  
     
     
         19 . A device for intracorporeal use within a patient's body, comprising: 
 an implantable scaffold;    at least one source of at least one therapeutic capable agent associated with at least a portion of the scaffold and configured to release the therapeutic capable agent within the patient's body; and    a swellable rate-controlling element disposed adjacent at least a portion of the source.    
     
     
         20 . A device as in  claim 19  wherein the rate-controlling element swells upon exposure to the intracorporeal environment  
     
     
         21 . A device as in  claim 20  wherein the rate-controlling element is configured to release the therapeutic capable agent from the source.