Biologically degradable compositions for medical applications

Abstract

A medical article is disclosed, comprising a biologically degradable AB block copolymer and a biologically degradable polymer that is capable, at equilibrium and at room temperature, of absorbing less than about 5 mass % water.

1 . A medical article, comprising:
 (a) a medical substrate; and   (b) a coating deposited on the substrate, the coating comprising a first polymer and a second polymer, wherein the first polymer is a biologically degradable AB block copolymer, and the second polymer is a biologically degradable polymer that is capable, at equilibrium and at room temperature, of absorbing less than about 5% water by mass of the biologically degradable polymer,   wherein the AB block copolymer is capable, at equilibrium and at room temperature, of absorbing about 5% or more water by mass of the AB block copolymer.   
     
     
         2 . The medical article of  claim 1 , wherein the ratio between the first polymer and the second polymer is between about 1:1 and about 1:99. 
     
     
         3 . The medical article of  claim 1 , wherein the ratio between the first polymer and the second polymer is between about 1:2 and about 1:49. 
     
     
         4 . The medical article of  claim 1 , wherein the ratio between the first polymer and the second polymer is between about 1:2 and about 1:19. 
     
     
         5 . The medical article of  claim 1 , wherein the medical article is a stent, graft, or a stent-graft. 
     
     
         6 . The medical article of  claim 1 , wherein the second polymer does not include or is substantially free of the AB polymeric blocks. 
     
     
         7 . The medical article of  claim 1 , wherein the AB block copolymer comprises a biocompatible polymeric moiety and a structural polymeric moiety. 
     
     
         8 . The medical article of  claim 7 , wherein the biocompatible polymeric moiety is selected from a group consisting of a poly(alkylene glycol), poly(2-hydroxyethyl methacrylate), poly(3-hydroxypropyl methacrylamide), hydroxylated poly(vinyl pyrrolidone), sulfonated dextran, sulfonated polystyrene, fibrin, fibrinogen, cellulose, starch, collagen, hyaluronic acid, heparin, a graft copolymer of poly(L-lysine)-graft-co-poly(ethylene glycol), and copolymers thereof. 
     
     
         9 . The medical article of  claim 8 , wherein the poly(alkylene glycol) is selected from a group consisting of poly(ethylene glycol), poly(propylene glycol), poly(tetramethylene glycol), and poly(ethylene oxide-co-propylene oxide). 
     
     
         10 . The medical article of  claim 7 , wherein the structural polymeric moiety is selected from a group consisting of poly(D,L-lactide), poly(caprolactone), poly(caprolactone-co-D,L-lactide), poly(butylene terephthalate), poly(ester amide), poly(aspirin), poly(L-lactide), poly(glycolide), poly(L-lactide-co-glycolide), poly(D,L-lactide-co-glycolide), poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(hydroxyvalerate), poly(3-hydroxybutyrate-co-valerate), poly(4-hydroxybutyrate-co-valerate), and polydioxanone. 
     
     
         11 . The medical article of  claim 1 , wherein the AB block copolymer has the formula: 
       
         
           
           
               
               
           
         
         wherein m, n, I, and K are positive integers. 
       
     
     
         12 . The medical article of  claim 1 , wherein the second polymer is selected from a group consisting of poly(L-lactide), poly(D,L-lactide), poly(glycolide), poly(L-lactide-co-glycolide), poly(D,L-lactide-co-glycolide), poly(caprolactone), poly(L-lactide-co-caprolactone), poly(D,L-lactide-co-caprolactone), polyhydroxyalkanoates, poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(hydroxyvalerate), poly(3-hydroxybutyrate-co-valerate), poly(4-hydroxybutyrate-co-valerate), poly(ester amides), poly(anhydrides), poly(carbonates), poly(trimethylene carbonate-co-glycolide), poly(trimethylene carbonate-co-L-lactide), poly(trimethylene carbonate-co-D,L-lactide), poly(dioxanone), poly(phosphazenes), poly(orthoesters), poly(tyrosine-co-carbonates), polyalkylene oxalates, poly(glycerol-co-sebacic acid esters), cyanoacrylates, poly(amino acids), poly(lysine), poly(glutamic acid) and combinations thereof. 
     
     
         13 . The medical article of  claim 1 , wherein the second polymer has the formula: 
       
         
           
           
               
               
           
         
         wherein n is a positive integer. 
       
     
     
         14 . The medical article of  claim 1 , additionally including a therapeutic substance. 
     
     
         15 . A method of treating a disorder in a human being, comprising:
 implanting in the human being a medical article of  claim 1 , wherein the disorder is selected from the group consisting of atherosclerosis, thrombosis, restenosis, hemorrhage, vascular dissection or perforation, vascular aneurysm, vulnerable plaque, chronic total occlusion, claudication, anastomotic proliferation for vein and artificial grafts, bile duct obstruction, ureter obstruction, tumor obstruction, and combinations thereof.