Patent ID: 8617592

Claim:
A zwitterionic conjugate, comprising a vesicle-forming lipid covalently coupled to a poly(carboxybetaine), a poly(sulfobetaine), or a poly(phosphobetaine), wherein the poly(carboxybetaine), poly(sulfobetaine), or poly(phosphobetaine) comprises a plurality of repeating units, each repeating unit having the formula: wherein R 1 is selected from the group consisting of hydrogen, fluorine, trifluoromethyl, C 1 -C 6 alkyl, and C 6 -C 12 aryl groups; R 2 and R 3 are independently selected from the group consisting of alkyl and aryl, or taken together with the nitrogen to which they are attached form a cationic center; L 1 is a linker that covalently couples the cationic center [N + (R 2 )(R 3 )] to the polymer backbone [â€”(CH 2 â€”CR 1 ) n â€”]; L 2 is a linker that covalently couples the anionic center [A(â•O)O âˆ’ ] to the cationic center; A is C, S, SO, P, or PO; M + is a counter ion associated with the (Aâ•O)O âˆ’ anionic center; X âˆ’ is a counter ion associated with the cationic center; and n is an integer from 1 to about 10,000.