Branched poly(-amino esters) for the delivery of nucleic acids

A method of delivering an agent to a subject, tissue, or cell, the method comprising administering to the subject or contacting the tissue or cell with a composition comprising:

• a branched polymer of Formula (I):
• L-Rn (I)
• or a salt thereof, wherein:
• L is a substituted or unsubstituted heteroalkylene;
• n is 3, 4, 5, or 6;
• and
• each R is independently hydrogen, Formula (II), or Formula (III);
• wherein Formula (II) is:
• wherein:
• m is an integer of 1-1000, inclusive;
• A is optionally substituted alkylene or optionally substituted heteroalkylene;
• X is —CH═CH2, —CH2CH2OR2, —CH2CH2SR3, —CH2CH2N(R2)(R3), or —CH2CH2L(R4)q;
• q is 2, 3, 4, or 5;
• R1 is optionally substituted alkyl or optionally substituted heteroalkyl;
• R2 is hydrogen, optionally substituted alkyl, or optionally substituted heteroalkyl;
• R3 is optionally substituted alkyl or optionally substituted heteroalkyl;
• or
• R2 and R3 combine to form a 4-7 membered ring;
• and
• each R4 is independently hydrogen, Formula (II), or Formula (III);
• wherein Formula (III) is:
• wherein:
• p is an integer of 1-1000, inclusive;
• B is optionally substituted alkylene or optionally substituted heteroalkylene;
• Z is —CH═CH2, —CH2CH2OR6, —CH2CH2SR7, —CH2CH2N(R6)(R7), or —CH2CH2L(R8)v;
• v is 2, 3, 4, or 5;
• R5 is optionally substituted alkyl or optionally substituted heteroalkyl;
• R6 is hydrogen, optionally substituted alkyl, or optionally substituted heteroalkyl;
• R7 is optionally substituted alkyl or optionally substituted heteroalkyl;
• or
• R6 and R7 combine to form a 4-7 membered ring;
• and
• each R8 is independently hydrogen, Formula (II), or Formula (III);
• provided that at least one R is Formula (II) or Formula (III), and provided that Formula (II) and Formula (III) are not the same;
• and
• an agent, wherein the agent is a polynucleotide.