Side-chain crystallizable polymers for medical applications
View Patent ↗Inherently radiopaque side-chain crystallizable polymers (IRSCCP's) are useful in various medical applications. An example of a IRSCCP is a polymer that comprises a main chain, a plurality of crystallizable side chains, and a plurality of heavy atoms attached to the polymer, the heavy atoms being present in an amount that is effective to render the polymer radiopaque. A polymeric material that includes a IRSCCP may be fabricated into a medical device useful for at least partially occluding a body cavity. For example, such a medical device may be an embolotherapy product.
1. A polymer comprising:
a main chain;
a plurality of crystallizable side chains; and
a plurality of heavy atoms attached to the polymer, the heavy atoms being present in an amount that is effective to render the polymer radiopaque,
wherein the polymer comprises a recurring unit of the formula (I):
wherein:
X 1 and X 2 are each independently selected from the group consisting of Br and I;
y 1 and y 2 are each independently zero or an integer in the range of 1 to 4;
A 1 is selected from the group consisting of
R 3 is selected from the group consisting of C 1 -C 30 alkyl, C 1 -C 30 heteroalkyl, C 5 -C 30 aryl, C 6 -C 30 alkylaryl, and C 2 -C 30 heteroaryl;
R 4 is selected from the group consisting of H, C 1 -C 30 alkyl, and C 1 -C 30 heteroalkyl;
R 1 is
Z is O or S;
R 5 and R 6 are each independently selected from the group consisting of —CH═CH—, —CHJ 1 -CHJ 2 -, and —(CH 2 ) a —;
a is zero or an integer in the range of 1 to 8;
J 1 and J 2 are each independently selected from the group consisting of Br and I; and
Q is a crystallizable group comprising from about 6 to about 30 carbon atoms after the recitation “radiopaque”.
2. The polymer of claim 1 having a melting point in the range of about 30° C. to about 80° C.
3. The polymer of claim 1 that is biocompatible.
4. The polymer of claim 1 that is bioresorbable.
5. The polymer of claim 1 in which the plurality of heavy atoms comprise an atom having an atomic number of at least 17.
6. The polymer of claim 5 in which the plurality of heavy atoms comprise an atom having an atomic number of at least 35.
7. The polymer of claim 1 in which the plurality of heavy atoms comprise an atom selected from the group consisting of bromine, iodine, bismuth, gold, platinum tantalum, tungsten, and barium.
8. The polymer of claim 1 in which the plurality of heavy atoms are covalently attached to the polymer.
9. The polymer of claim 1 in which the plurality of heavy atoms are ionically attached to the polymer.
10. The polymer of claim 1 that is a copolymer comprising at least two different recurring units.
11. The polymer of claim 10 that is a random copolymer.
12. The polymer of claim 10 that is a block copolymer.
13. The polymer of claim 1 in which the heavy atoms are attached to the polymer in a manner that minimizes disruption of side chain crystallinity.
14. The polymer of claim 1 in which Q comprises from about 20 to about 30 carbon atoms.
15. The polymer of claim 1 in which R 5 is —CH═CH— or —(CH 2 ) a —; R 6 is —(CH 2 ) a —; and Q is an ester group comprising from about 10 to about 30 carbon atoms.