Zwitterionic copolymers, method of making and use on medical devices
Biocompatible copolymers are manufactured to include a zwitterionic monomer and an alkoxy acrylate monomer. The alkoxy acrylate monomer can be a 2-methoxyethyl methacrylate (MOEMA) or 2-ethoxyethyl methacrylate (EOEMA). Alternatively, the alkoxy acrylate can be 2-methoxyethyl acrylate (MOEA) or 2-ethoxyethyl acrylate (EOEA). The alkoxy acrylate monomers advantageously give the zwitterionic copolymers greater ductility, strength, and toughness while maintaining a desired amount of hydrophilicity. The improved toughness allows the zwitterionic copolymers to be processed without cross-linking, which improves the elongation properties of the zwitterionic copolymer, and reduces the risk of cracking during use.
1. A biocompatible polymer of the chemical formula:
in which,
R 1 and R 2 are independently a hydrogen or methyl;
R 3 is a zwitterion group having the formula:
in which
A 5 is selected from the group consisting of —O—, —S— and —NH—;
R 16 is selected from the group consisting of alkanediyl, —C(O)alkylene- and —C(O)NHalkylene-;
the R 3 17 groups are independently selected from the group consisting of hydrogen, 1 to 4 carbon atoms or, taken together with the nitrogen to which they are bonded , a heterocyclic ring of 5 to 7 atoms;
R 5 is an ethyl or methyl;
n is in an range from about 0.01 to about 0.75; and
m is in a range from about 0.25 to about 0.99.
2. A biocompatible polymer as in claim 1 , in which R 5 is a methyl.
3. A biocompatible polymer as in claim 1 , in which R 5 is an ethyl.
4. The biocompatible polymer of claim 1 , wherein R 3 is selected from the group consisting of phosphorylcholine, phosphorylethanolamine, phosphatidylethanolamine, phosphatidylserine, sulfobetaine and combinations thereof.
5. The biocompatible polymer of claim 1 , wherein the copolymer has a number average molecular weight of about 20 kD to about 800 kD.