Lipid-like nanocomplexes and uses thereof

1. A compound having a structure represented by Formula (I):

or a pharmaceutically acceptable salt thereof,

wherein

A, a hydrophilic head, is selected from:

wherein:

R a and R a ′ are each independently selected from H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 1 -C 20 heteroalkyl, C 1 -C 20 heterocycloalkyl, C 6 monocyclic aryl, and 5-8 monocyclic heteroaryl; and

Z is selected from a C 1 -C 20 bivalent aliphatic radical and a C 1 -C 20 bivalent heteroaliphatic radical;

B is

wherein

R 1 and R 2 are each independently at each occurrence a C 1 -C 20 bivalent aliphatic radical;

R 3 and R 4 are each independently at each occurrence selected from H and C 1 -C 10 alkyl; or, alternatively, R 3 and R 4 , together with the atom to which they are attached, form C 3 -C 10 cycloalkyl;

R 5 is independently at each occurrence selected from C 1 -C 24 alkyl, C 2 -C 24 alkenyl, C 2 -C 24 alkynyl, C 3 -C 24 cycloalkyl, C 1 -C 24 heteroalkyl, C 1 -C 24 heterocycloalkyl, aryl, and heteroaryl;

W is independently at each occurrence selected from O, S, and Se;

V is independently at each occurrence selected from a bond, O, S, and Se;

X is independently at each occurrence selected from

wherein:

L 1 , L 2 , L 3 , and L 4 are each independently at each occurrence selected from a bond, O, S, and NR c ;

G is independently at each occurrence selected from O, S, and NR d ;

Q is independently at each occurrence selected from OR f , SR g , and NR h R i ;

r and t are each independently at each occurrence an integer from 1 to 6;

wherein R c , R d , R f , R g , R h , and R i are each independently at each occurrence selected from H, C 1 -C 10 alkyl, C 1 -C 10 heteroalkyl, aryl, and heteroaryl; and

m is 1; and

at least one of W and V is Se.

2. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein one and only one of W and V is Se.

3. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein W is Se; and V is a bond.

4. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein W is at each occurrence Se.

5. The compound or the pharmaceutically acceptable salt thereof of claim 4 , wherein V is at each occurrence a bond.

6. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein, in B, X is selected from

wherein R c and R d are each independently at each occurrence selected from H, C 1 -C 10 alkyl, C 1 -C 10 heteroalkyl, aryl, and heteroaryl.

7. The compound or the pharmaceutically acceptable salt thereof of claim 6 , wherein R c and R d are each independently at each occurrence selected from H and C 1 -C 10 alkyl.

8. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein R 1 and R 2 are each independently at each occurrence a C 1 -C 4 bivalent aliphatic radical.

9. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein R 3 and R 4 are each independently at each occurrence selected from H and C 1 -C 4 alkyl.

10. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein R 5 is C 1 -C 20 alkyl.

11. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein A is an amino moiety formed from one of the following amines:

12. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein A is an amino moiety formed from one of the following amines:

13. A pharmaceutical composition, comprising the compound or the pharmaceutically acceptable salt thereof of claim 1 ; and a therapeutic agent.

14. The pharmaceutical composition of claim 13 , wherein the therapeutic agent comprises a protein or a nucleic acid.

15. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein A is an amino moiety formed from one of the following amines:

16. The compound or the pharmaceutically acceptable salt thereof of claim 1 , wherein the compound is