Medical device with sponge coating for controlled drug release

Abstract

The medical devices of the invention comprise an expandable portion which is covered with a sponge coating for release of at least one biologically active material. The sponge coating is made of a non-hydrogel polymer having a plurality of voids. The device can further include means for infusing or expelling the biologically active material or drug into the voids. The drug is delivered to the body lumen of a patient by expelling the drug and inflating or expanding the expandable portion of the catheter or device.

1 - 46 . (canceled) 
     
     
         47 . A medical device having at least an expandable portion which is insertable or implantable into a body lumen of a patient,
 wherein at least a part of the expandable portion is covered with a coating to form an exposed outermost surface for release of at least one biologically active material;   wherein the coating comprises a non-hydrogel polymer having a plurality of voids;   wherein the voids contain at least one biologically active material; and   wherein the voids are formed by eluting a particulate material from the polymer.   
     
     
         48 . The device of  claim 47  wherein the device is a catheter for delivering the biologically active material and wherein the expandable portion is expandable in response to expansion pressure to substantially fill the cross-section of the lumen and engage the tissue of the lumen. 
     
     
         49 . The device of  claim 48  wherein the expandable portion is a balloon. 
     
     
         50 . The device of  claim 47  wherein the biologically active material comprises an anti-proliferative agent. 
     
     
         51 . The device of  claim 47  wherein the biologically active material comprises an agent selected from the group of taxol and its analogs and derivatives. 
     
     
         52 . The device of  claim 47  wherein the non-hydrogel polymer comprises an elastomeric polymer. 
     
     
         53 . The device of  claim 47  wherein the non-hydrogel polymer is selected from the group of polyisobutylene and its copolymers. 
     
     
         54 . A stent implantable into a body lumen of a patient,
 wherein at least a part of the stent is covered with a coating to form an exposed outermost surface for release of at least one biologically active material;   wherein the coating comprises a non-hydrogel polymer having a plurality of voids;   wherein the voids contain at least one biologically active material; and   wherein the voids are formed by eluting a particulate material from the polymer.   
     
     
         55 . The stent of  claim 54  wherein the stent is a balloon-expandable stent. 
     
     
         56 . The stent of  claim 54  wherein the stent is a self-expanding stent. 
     
     
         57 . The stent of  claim 54  wherein the biologically active material comprises an anti-proliferative agent. 
     
     
         58 . The stent of  claim 54  wherein the biologically active material comprises an agent selected from the group of taxol and its analogs and derivatives. 
     
     
         59 . The stent of  claim 54  wherein the non-hydrogel polymer comprises an elastomeric polymer. 
     
     
         60 . The stent of  claim 54  wherein the non-hydrogel polymer is selected from the group of polyisobutylene and its copolymers. 
     
     
         61 . A method of delivering a biologically active material to a desired location of a body lumen of a patient comprising:
 a) forming a coating on a surface of an expandable portion of a medical device for insertion or implantation into the body of a patient, wherein the expandable portion has a surface which is adapted for exposure to body tissue of the patient, the forming done by:
 i) applying a composition comprising a non-hydrogel polymer and a particulate material to the surface, and 
 ii) exposing the composition to a solvent to elute the particulate material from the polymer to form a plurality of voids therein; 
   b) loading the coating with the biologically active material;   c) delivering the expandable portion of the medical device to a target location in the body of the patient; and   d) expanding the expandable portion of the medical device at the target location to deliver the biologically active material.   
     
     
         62 . The method of  claim 61  wherein the expandable portion of the medical device comprises a balloon. 
     
     
         63 . The method of  claim 61  wherein the expandable portion of the medical device comprises a stent. 
     
     
         64 . The method of  claim 61  wherein the biologically active material comprises an anti-proliferative agent. 
     
     
         65 . The method of  claim 61  wherein the biologically active material comprises an agent selected from the group of taxol and its analogs and derivatives. 
     
     
         66 . The method of  claim 61  wherein the non-hydrogel polymer comprises an elastomeric polymer.