Implantable medical devices fabricated from polymers with radiopaque groups

Abstract

Inplantable medical devices fabricated from radiopaque polymers are disclosed.

1 . A stent formed from a biodegradable polymer material, wherein radiopaque functional groups are chemically bonded to at least some of polymers of the polymer material. 
   
   
       2 . The stent of  claim 1 , wherein the radiopaque functional groups are selected from the group consisting of iodine, triiodobenzoyl chloride, and triidobenzoic acid. 
   
   
       3 . The stent of  claim 1 , wherein the polymer material comprises an unbranched polymer. 
   
   
       4 . The stent of  claim 1 , wherein the polymer material comprises a star polymer. 
   
   
       5 . The stent of  claim 1 , wherein the radiopaque functional groups are chemically bonded to the backbone of at least some of the polymers of the polymer material, 
   
   
       6 . The stent of  claim 5 , wherein the radiopaque functional group is added by removal of a proton of a methylene group in an a position of an ester carbonyl on the backbone. 
   
   
       7 . The stent of  claim 1 , wherein the radiopaque functional groups are chemically bonded to end groups of at least some of the polymers of the polymer material. 
   
   
       8 . The stent of  claim 1 , wherein the biodegradable polymer material comprises a blend of an unbranched semi-crystalline polymer and a star copolymer, wherein the radiopaque functional groups are chemically bonded to the star copolymer. 
   
   
       9 . The stent of  claim 1 , wherein the polymers of the polymer material are selected from the group consisting of poly(L-lactide), poly(DL-lactide), polycaprolactone, polyglycolide, and copolymers thereof. 
   
   
       10 . An implantable medical device comprising structural elements fabricated at least in part from a polymer blend comprising:
 a biodegradable matrix polymer blended with biodegradable linear block copolymers, the linear block copolymers having a discrete phase segment and a continuous phase segment, wherein the discrete phase segment is immiscible with the matrix polymer such that discrete phase segments form a discrete phase within the matrix polymer, wherein the continuous phase segment is miscible with the matrix polymer, wherein radiopaque functional groups are chemically bonded to the discrete phase segments, the continuous phase segments, or both.   
   
   
       11 . The device of  claim 10 , wherein the implantable medical device is a stent. 
   
   
       12 . The device of  claim 10 , wherein the radiopaque functional groups are selected from the group consisting of iodine, triiodobenzoyl chloride, and triidobenzoic acid. 
   
   
       13 . The device of  claim 10 , wherein the radiopaque functional groups are chemically bonded to the ends of the continuous phase segments, the discrete phase segments, or both. 
   
   
       14 . The device of  claim 10 , wherein the radiopaque functional groups are chemically bonded along the backbone of the discrete phase segments. 
   
   
       15 . The device of  claim 14 , wherein the radiopaque functional group is added by removal of a proton of a methylene group in an a position of an ester carbonyl on the backbone. 
   
   
       16 . The device of  claim 10 , wherein the block copolymers are dispersed throughout the matrix polymer. 
   
   
       17 . The device of  claim 10 , wherein the discrete phase segments are faster degrading than the continuous phase segments and the matrix polymer. 
   
   
       18 . The device of  claim 10 , wherein the discrete phase segments are of the same or similar chemical composition as the matrix polymer. 
   
   
       19 . The device of  claim 10 , wherein the discrete phase segments have a Tg below body temperature so that the discrete phase is elastic at physiological conditions, and wherein the continuous phase segments and the matrix polymer have a Tg above body temperature so that the continuous phase is glassy at physiological conditions. 
   
   
       20 . The device of  claim 10 , wherein the matrix polymer and the continuous phase segments comprise PLLA. 
   
   
       21 . The device of  claim 10 , wherein the discrete phase segments comprise units selected from the group consisting of CA, TMC, and dioxanone. 
   
   
       22 . The device of  claim 10 , wherein 1 to 20 wt % of the polymer blend comprises the linear block copolymer. 
   
   
       23 . The device of  claim 10 , wherein the structural elements comprise a first layer comprising the polymer blend and a second layer comprising a majority of the linear block copolymer including the radiopaque functional groups chemically bonded to the discrete phase segments, the continuous phase segments, or both. 
   
   
       24 . An implantable medical device comprising structural elements fabricated at least in part from a polymer blend comprising:
 a biodegradable matrix polymer blended with biodegradable star-block copolymers, the star-block copolymers having at least three arms, wherein the arms include inner segments and outer segments, the inner segments being immiscible with the matrix polymer and forming a discrete phase within the matrix polymer, wherein the outer segments are miscible with the matrix polymer, wherein radiopaque functional groups are chemically bonded to the inner segments or the outer segments.   
   
   
       25 . The device of  claim 24 , wherein the implantable medical device is a stent. 
   
   
       26 . The device of  claim 24 , wherein the radiopaque functional groups are selected from the group consisting of iodine, triiodobenzoyl chloride and triidobenzoic acid. 
   
   
       27 . The device of  claim 24 ,-wherein the radiopaque functional groups are chemically bonded to one or more of the ends of the outer segments. 
   
   
       28 . The device of  claim 24 , wherein the radiopaque functional groups are chemically bonded along the backbone of the inner segments. 
   
   
       29 . The device of  claim 28 , wherein the radiopaque functional group is added by removal of a proton of a methylene group in an a position of an ester carbonyl on the backbone. 
   
   
       30 . The device of  claim 24 , wherein the star-block copolymers are dispersed throughout the matrix polymer. 
   
   
       31 . The device of  claim 24 , wherein the inner segments are faster degrading than the outer segments. 
   
   
       32 . The device of  claim 24 , wherein the outer segments are of the same or similar chemical composition as the matrix polymer. 
   
   
       33 . The device of  claim 24 , wherein the inner segments have a Tg below body temperature so that the discrete phase is elastic at physiological conditions, and wherein the outer segments and the matrix polymer have a Tg above body temperature so that the continuous phase is glassy at physiological conditions. 
   
   
       34 . The device of  claim 24 , wherein the matrix polymer and the outer segments comprise PLLA. 
   
   
       35 . The device of  claim 24 , wherein the inner segments comprise units selected from the group consisting of CL, TMC, and dioxanone. 
   
   
       36 . The device of  claim 24 , wherein 1 to 20 wt % of the polymer blend comprises the star-block copolymer. 
   
   
       37 . The device of  claim 24 , wherein the structural elements comprise a first layer comprising the polymer blend and a second layer comprising a majority of the star block copolymer including the radiopaque functional groups chemically bonded to the inner segments, the outer segments, or both.