Multifunctional zwitterionic polymer conjugates

1. A random copolymer comprising a first monomer and a second monomer, wherein the first monomer comprises a phosphorylcholine, and the second monomer is linked to a first functional agent, wherein the first and the second monomer are each independently selected from the group consisting of acrylates, methacrylates, acrylamides, methacrylamides, styrenes, vinyl-pyridine and vinyl-pyrrolidone, and are distributed randomly throughout the polymer, and the random copolymer has multiple polymer arms extending from a branched initiator fragment.

2. The random copolymer of claim 1 , wherein the branched initiator fragment is linked to a second functional agent.

3. The random copolymer of claim 2 , wherein the first functional agent is different from the second functional agent.

4. The random copolymer of claim 1 , wherein the branched initiator fragment is selected from the group consisting of an alkane, a cycloalkane, an alkyl carboxylic acid, an ester of an alkyl carboxylic acid, a cycloalkylcarboxylic acid, an ester of a cycloalkylcarboxylic acid, an ether, a cyclic alkyl ether, an alkyl aryl group, an alkyl amide, an alkyl-aryl carboxylic acid, and an ester of an alkyl-aryl carboxylic acid.

5. The random copolymer of claim 1 , wherein the first monomer comprises 2-(methacryloyloxy)ethyl (2-(trimethylammonio)ethyl) phosphate.

6. The random copolymer of claim 1 , wherein the polymer has 2, 3, 4, 5, 6, 7, 8 or 9 polymer arms.

7. The random copolymer of claim 1 , which comprises from about 100 to about 1,000 first monomers, and from about 100 to about 1,000 second monomers.

8. The random copolymer of claim 1 , which comprises from about 10 to about 5,000 first monomers, and from about 10 to about 5,000 second monomers.

9. The random copolymer of claim 8 , wherein the second monomers are present relative to the first monomers in a ratio of 100:1, 50:1, 40:1, 30:1, 20:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:20, 1:30, 1:40, 1:50 or 1:100.

10. The random copolymer of claim 8 , which has a weight average molecular weight of from about 1000 to about 1,500,000 Daltons, as determined by a light scattering technique.

11. The random copolymer of claim 10 , which has a polydispersity less than about 1.5, as determined by gel permeation chromatography.

12. The random copolymer of claim 1 , wherein the second monomer is linked to the first functional agent through a cleavable linker.

13. The random copolymer of claim 12 , wherein the cleavable linker is selected from the group consisting of a hydrolyzable linker, an enzymatically cleavable linker, a pH sensitive linker, a disulfide linker, and a photolabile linker.

14. The random copolymer of claim 1 , wherein the second monomer is linked to the first functional agent through a non cleavable linker.

15. The random copolymer of claim 1 , wherein the second monomer is linked to the first functional agent through the linker which comprises a triazole ring.

16. The random copolymer of claim 1 , wherein the first functional agent is selected from the group consisting of a bioactive agent, a detection agent, an imaging agent, a labeling agent, and a diagnostic agent.

17. The random copolymer of claim 1 , wherein the first functional agent is a bioactive agent.

18. The random copolymer of claim 17 , wherein the bioactive agent is a therapeutic protein.

19. The random copolymer of claim 17 , wherein the bioactive agent is an antibody or antibody fragment.

20. The random copolymer of claim 17 , wherein the bioactive agent is a drug.

21. A method of making a random copolymer of claim 1 , the method comprising the step of contacting a mixture of a first monomer and a second monomer with a branched initiator under conditions sufficient to prepare a multiple arms random copolymer via free radical polymerization, wherein the first monomer comprises a phosphorylcholine, and the second monomer is linked to a functional agent.