Adhesion promoting temporary mask for coated surfaces

Abstract

An expandable medical device includes a plurality of elongated struts, forming a substantially cylindrical device which is expandable from a first diameter to a second diameter. A plurality of different beneficial agents may be loaded into different openings within the struts for delivery to the tissue. For treatment of conditions such as restenosis, different agents are loaded into different openings in the device to address different biological processes involved in restenosis and are delivered at different release kinetics matched to the biological process treated. The different agents may also be used to address different diseases from the same drug delivery device. In addition, anti-thrombotic agents may be affixed to at least a portion of the surfaces of the medical device for the prevention of sub-acute thrombosis. To ensure that the different agents remain affixed to the device as well as to each other, masking and de-masking processes may be utilized.

1 . A method of coating an intraluminal scaffold having a plurality of openings therein, the method comprising:
 applying a mask to interior surfaces of the plurality of openings in the intraluminal scaffold;   applying a coating to the surfaces of the intraluminal scaffold, the coating comprising an anti-thrombotic material;   removing the mask and any coating adhered to the mask from the interior surfaces of the plurality of openings in the intraluminal scaffold; and   filling the plurality of openings with one or more therapeutic agents.   
     
     
         2 . The method of coating an intraluminal scaffold according to  claim 1 , wherein the step of applying a mask comprises contacting the interior surfaces of the plurality of openings with a solution of a polymer and a first solvent for at least one time. 
     
     
         3 . The method of coating an intraluminal scaffold according to  claim 1 , wherein the step of applying a coating comprises contacting the surfaces of the intraluminal stent with at least a primer layer for the anti-thrombotic material followed by contacting the primer layer with the anti-thrombotic coating. 
     
     
         4 . The method of coating an intraluminal scaffold according to  claim 3 , wherein the step of removing the mask comprises contacting the mask with a second solvent and applying ultrasonic energy to the second solvent while in the plurality of openings. 
     
     
         5 . The method of coating an intraluminal scaffold according to  claim 3 , wherein the step of removing the mask comprises contacting the mask with a second solvent and applying thermal energy to the second solvent while in the plurality of openings. 
     
     
         6 . An implantable medical device comprising:
 a substantially cylindrical intraluminal scaffold having a luminal surface and an abluminal surface, the distance between the luminal surface and the abluminal surface defining the wall surfaces of the intraluminal scaffold, the intraluminal scaffold also including a plurality of openings defining interior surfaces;   an anti-thrombotic coating affixed to the luminal, abluminal and wall surfaces of the intraluminal scaffold; and   at least one therapeutic agent deposited in at least one of the plurality of openings and making direct contact with the interior surfaces thereof.   
     
     
         7 . The implantable medical device according to  claim 6 , wherein the anti-thrombotic agent comprises a polysaccharides. 
     
     
         8 . The implantable medical device according to  claim 7 , wherein the polysaccharide comprises sulfated polysaccharides. 
     
     
         9 . The implantable medical device according to  claim 7 , wherein the polysaccharide comprises heparin. 
     
     
         10 . The implantable medical device according to  claim 6 , wherein at least one therapeutic agent comprises a combination of a polymer and at least one agent selected from the group consisting of an anti-restenotic, an anti-inflammatory, an anti-thrombotic, an anti-proliferative and a cardioprotectant. 
     
     
         11 . The implantable medical device according to  claim 10 , wherein the polymer comprises a biostable polymer. 
     
     
         12 . The implantable medical device according to  claim 11 , wherein the biostable polymer is selected from the group consisting of polymethacrylate, polyacrylate and polystyrene. 
     
     
         13 . The implantable medical device according to  claim 10 , wherein the polymer comprises a bioabsorbable polymer. 
     
     
         14 . The implantable medical device according to  claim 13 , wherein the bioabsorbable polymer is selected from the group consisting of polylactide, poly(lactic-co-glycolic acid) and poly(glycolide-co-caprolactone).