Patent ID: 7371781

Claim:
A drug delivery composition comprising (a) a mixed polymeric micelle comprising an inner core and an outer shell, wherein the mixed polymeric micelle comprises a mixture of (i) an amphiphilic block copolymer comprising an AB-block copolymer comprising a poly(ethylene glycol)-poly(L-histidine) block copolymer or a poly(ethylene glycol)-poly(L-lactic acid) block copolymer or a poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) block copolymer, or an ABA-block copolymer comprising a poly(ethylene glycol)-poly(L-lactic acid)-poly(ethylene glycol) block copolymer or a poly(ethylene glycol)-poly(lactic acid-co-glycolic acid)-poly(ethylene glycol) block copolymer, or a BAB-block copolymer comprising a poly(L-lactic acid)-poly(ethylene glycol)-poly(L-lactic acid) block copolymer or a poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) block copolymer, or an (AB) n alternating multiblock copolymer comprising a (poly(ethylene glycol)-poly(L-lactic acid)) n alternating multiblock copolymer or a (poly(ethylene glycol)-poly(lactic acid-co-glycolic acid)) n alternating multiblock copolymer, and (ii) a pH-sensitive block copolymer having a ligand covalently bonded thereto, wherein the pH-sensitive block copolymer comprises an extended configuration at less than about pH 7.0 and a globular configuration at about pH 7.4 or greater, and wherein the pH-sensitive block copolymer having a ligand covalently bonded thereto comprises a ligand/AB-block copolymer comprising a ligand-poly(L-histidine)-poly(L-lactic acid) block copolymer or a ligand-poly(L-histidine)-poly(lactic acid-co-glycolic acid) block copolymer, or a ligand/ABA-block copolymer comprising a ligand-poly(L-histidine)-poly(ethylene glycol)-poly(L-histidine) block copolymer, or a ligand/BAC-block copolymer comprising a ligand-poly(ethylene glycol)-poly(L-histidine)-poly(L-lactic acid) block copolymer or a ligand-poly(ethylene glycol)-poly(L-histidine)-poly(lactic acid-co-glycolic acid) block copolymer, or a ligand/BABA-block copolymer comprising a ligand-poly(ethylene glycol)-poly(L-histidine)-poly(ethylene glycol)-poly(L-histidine) block copolymer, or a ligand/BABC-block copolymer comprising a ligand-poly(ethylene glycol)-poly(L-histidine)-poly(ethylene glycol)-poly(L-lactic acid) or a ligand-poly(ethylene glycol)-poly(L-histidine)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid), or a ligand/block copolymer comprising a ligand-poly(L-histidine)-poly(ethylene glycol)-poly(L-lactic acid) block copolymer; and (b) a drug disposed in the inner core.