BISPECIFIC INTRACELLULAR DELIVERY VEHICLES
A composition for delivering an agent to a cell, comprising a bispecific affinity reagent and a pH-responsive, membrane destabilizing polymer. The bispecific affinity reagent may include a first affinity reagent covalently linked to a second affinity reagent, wherein the first affinity reagent binds to a molecule on the surface of a cell, and the second affinity reagent binds to an intracellular target.
1 - 47 . (canceled)
48 . A composition comprising:
a bispecific affinity reagent comprising a first affinity reagent covalently linked to a second affinity reagent, wherein the first affinity reagent binds to a molecule on the surface of a cell and the second affinity reagent binds to an intracellular target, and wherein the bispecific affinity reagent is a bispecific antibody; and
a pH-responsive, membrane destabilizing polymer.
49 . The composition of claim 48 , wherein the bispecific antibody is selected from the group consisting of a tandem scFv, a heterodimeric scFv, a diabody, a minibody, a quadroma, and an scFv recombinantly fused to a whole antibody.
50 . The composition of claim 48 , wherein the bispecific antibody is a humanized antibody.
51 . The composition of claim 48 , wherein the first and second affinity reagents are present in a single polypeptide chain.
52 . The composition of claim 48 , wherein the bispecific affinity reagent is produced in a host cell as two separately encoded polypeptide chains that are linked by disulfide bonds.
53 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises a plurality of pendant linking groups, and wherein the bispecific affinity reagent is linked to the polymer via the plurality of pendant linking groups.
54 . The composition of claim 48 , wherein the bispecific affinity reagent is cleavably linked to the polymer through a pH-sensitive bond.
55 . The composition of claim 54 , wherein the pH-sensitive bond is a hydrazone or acetal.
56 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer is a copolymer.
57 . The composition of claim 56 , wherein the pH-responsive, membrane destabilizing polymer is a block copolymer.
58 . The composition of claim 57 , wherein the pH-responsive, membrane destabilizing polymer is a diblock copolymer.
59 . The composition of claim 57 , wherein the block copolymer comprises a hydrophobic, membrane destabilizing block and a hydrophilic block.
60 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer has a polydispersity index (PDI) of less than 2.0.
61 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer is produced using controlled radical polymerization.
62 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises monomeric residues derived from polymerization of ethylenically unsaturated monomers.
63 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises monomeric residues derived from polymerization of a (C 2 -C 8 ) alkylacrylic acid.
64 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises monomeric residues derived from polymerization of a (C 2 -C 8 ) alkyl-ethacrylate, a (C 2 -C 8 ) alkyl-methacrylate, or a (C 2 -C 8 ) alkyl-acrylate.
65 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises monomeric residues derived from polymerization of N,N-di(C 1 -C 6 )alkyl-amino(C 1 -C 6 )alkyl-ethacrylate, N,N-di(C 1 -C 6 )alkyl-amino(C 1 -C 6 )alkyl-methacrylate, or N,N-di(C 1 -C 6 )alkyl-amino(C 1 -C 6 )alkyl-acrylate.
66 . The composition of claim 48 , wherein the pH-responsive, membrane destabilizing polymer comprises a random copolymer chain having monomeric residues derived from polymerization of propyl acrylic acid, N,N-dimethylaminoethylmethacrylate, and butyl methacrylate.
67 . The composition of claim 66 , wherein the pH-responsive, membrane destabilizing polymer is a block copolymer comprising said random copolymer chain as a membrane disrupting polymer block, and further comprising one or more additional blocks.