Block copolymers

A composition comprising:

• a) a block copolymer of the formula I
• T1-L1-[A]x-[B]y—Z I
• wherein
• T1 is a first targeting moiety;
• L1 is absent or a linking moiety;
• A is a first block that is a polymer formed from monomers comprising formula A2 or a random copolymer formed from monomers comprising formulae A2 and A3;
• A2, A4 and A5;
• A2 and A5;
• or A4 and A5;
• wherein n is 1-120, R3 is H or C1-C6 alkyl, R4 is S, O, NH or N(C1-C6 alkyl), R5 is O or S and R6 is H, C1-C6 alkyl, C1-C6 alkyl-NH2, C1-C6 alkyl-NH(C1-C6 alkyl), C1-C6 alkyl-N(C1-C6 alkyl)2;
• wherein R7 and R10 are independently H or C1-C6 alkyl, R8 is S, O, NH or N(C1-C6 alkyl), and R9 is O or S and R11 is an amine protecting group;
• wherein n is 1-230, R17 is H or C1-C6 alkyl, R18 is O, S, NH or N(C1-C6 alkyl), R19 is O or S, and R20 is OH, NH, H, T2, or C1-C6 alkyl, where T2 is a second targeting moiety;
• wherein R21 is H or C1-C6 alkyl, R22 is O, NH or N(C1-C6 alkyl), R23 is H, aryl, arylhalide, alkyl, alkyl alcohol;
• B is a second block that is a random copolymer formed from monomers comprising formulae B1, B2, B3 and B4
• wherein R12, R13, R14, R15, R16 and R17 are independently H or C1-C6 alkyl, R18 is O, S, NH, N(C1-C6 alkyl), or (OCH2CH2)1-120, and Q is selected from the group consisting of (i) S—S-G, (ii) (OCH2CH2)1-120—S—S-G, (iii) V-L3-G wherein V is an amide, ester, imine, oxime, thioester, product of a [3+2] cycloaddition, product of a [4+1] cycloaddition, carbonate, carbamate, urea, acetal, ketal, or hydrazone, and L3 is C1-C6 alkyl, (OCH2CH2)1-50, C1-C6 alkyl-(OCH2CH2)1-50, or thioether,
• wherein R29 is C1-C6 alkyl, (OCH2CH2)1-50, C1-C6 alkyl-(OCH2CH2)1-50, O, NH, or N(C1-C6 alkyl), and (vii) S—S-L2-G wherein L2 is
• wherein n=1-35 and designates a point of attachment of L2 to G,
• wherein G is a cationic peptide, polyamine, or polycation;
• x is 2-20 kDa;
• y is 2-20 kDa;
• the ratio of x to y is from 2:1 to 1:4;
• and
• Z is H, SH, C(CH3)2CN,
• wherein R24 is S—(C1-C12 alkyl), aryl, arylhalide, O-(C1-C12 alkyl), or NR25R26 wherein R25 and R26 are independently H, alkyl, aryl, or heteroaryl;
• and designates a point of attachment;
• and
• b) an oligonucleotide.