Multivalent ionizable lipid delivery systems

A compound represented by the structure of Formula (A):

• wherein,
• R1 is hydroxyl, amino, or C1-C6 alkoxy substituted with one or more of oxo and heteroaryl;
• R2 is hydrogen or hydroxyl;
• R3 and R4 are each independently hydrogen, C1-C20 alkyl, or C2-C20 alkenyl;
• R5 is C3-C20 alkyl, C2-C20 alkenyl,
• wherein,
• R6 and R7 are each independently hydrogen, C1-C20 alkyl, or C2-C20 alkenyl;
• p is an integer from 1 to 8;
• n is an integer from 0 to 6;
• and
• q is an integer from 2 to 6.

A compound represented by the structure of Formula (B):

• wherein,
• each R1 is independently amino or hydroxyl;
• each R2 is independently hydrogen or hydroxyl;
• x is an integer from 0 to 6;
• p is an integer from 1 to 4;
• each R9 is independently represented by the structure:
• wherein,
• R2′ is hydrogen or hydroxyl;
• R3 and R4 are each independently hydrogen, C1-C20 alkyl, or C2-C20 alkenyl;
• m is an integer from 0 to 2;
• and
• y is an integer from 1 to 6.

A method for transfecting a cell with a nucleic acid, the method comprising contacting the cell with a complex comprising the nucleic acid and a compound represented by the structure of Formula (A):

• wherein,
• R1 is hydroxyl, amino, or C1-C6 alkoxy substituted with one or more of oxo and heteroaryl;
• R2 is hydrogen or hydroxyl;
• R3 and R4 are each independently hydrogen, C1-C20 alkyl, or C2-C20 alkenyl;
• R5 is C3-C20 alkyl, C2-C20 alkenyl,
• wherein,
• R6 and R7 are each independently hydrogen, C1-C20 alkyl, or C2-C20 alkenyl;
• p is an integer from 1 to 8;
• n is an integer from 0 to 6;
• and
• q is an integer from 1 to 6.