Lipids and complexes for the delivery of biologically-active material to cells

1. An ionic compound of formula (Ia):

wherein:

each of X and Y are the same or different and is selected from —O—, and —O—C(O)— where the carbonyl carbon is bonded to group R 1 or R 2 ;

R 1 and R 2 are the same or different and are each independently a C 12-24 hydrocarbyl group which is unsubstituted or substituted by one or more substituents selected from the group consisting of hydroxy, halogen and OR A , wherein R A is a C 1-6 hydrocarbyl group;

R 3 and R 4 are the same or different and are each independently a C 1-10 hydrocarbyl group which is unsubstituted or substituted by one or more substituents selected from the group consisting of hydroxy, halogen, —OR, —C(O)OH, —CN, —N(R′) 2 , and —C(O)R, wherein each R is the same or different and is a C 1-6 hydrocarbyl group;

Sp and W are together a bond; or

Sp is a C 1-8 alkylene group which is unsubstituted or substituted by one or more substituents selected from the group consisting of hydroxy, halogen and OR, wherein R is a C 1-6 hydrocarbyl group; and W is selected from the group consisting of a bond, —O—C(O)—, —C(O)—O— and —O—; each B is the same or different and is a C 1-6 alkylene group which is unsubstituted or substituted by one or more substituents selected from the group consisting of hydroxy, halogen, —OR A , —NR A R A and —OC(O)R A ;

wherein each R A is independently selected from C 1-4 hydrocarbyl;

in is an integer from 1 to 8; and

Q is —OR 5 or —O—C(O)—R 5 , wherein R 5 is selected from a C 12-24 hydrocarbyl group which is unsubstituted or substituted by one or more substituents selected from hydroxy, halogen and OR A , wherein R A is a C 1-6 hydrocarbyl group.

2. The ionic compound of claim 1 wherein R 1 and R 2 are the same or different and are each independently a C 14-22 hydrocarbyl group having one or more double bonds.

3. The ionic compound of claim 1 wherein either Sp and W are both bond, or Sp is an unsubstituted C 1-8 alkylene group and W is bond, —C(O)—O— or —O—.

4. The ionic compound of claim 1 wherein R 3 and R 4 may be the same or different and each is a straight or branched, unsubstituted C 1-4 alkyl group.

5. The ionic compound of claim 1 wherein each B is selected from an unsubstituted C 1-3 alkylene group.

6. The ionic compound of claim 1 wherein m is 1, 2, 3, 4, 5 or 6.

7. The ionic compound of claim 1 , wherein R 1 and R 2 are the same or different and are each independently a C 14-22 hydrocarbyl group having one double bond; Sp and W are both bond; R 3 and R 4 are each a straight or branched, unsubstituted C 1-4 alkyl group; each B is selected from an unsubstituted C 1-3 alkylene group; m is 2, 3, 4, 5 or 6; and Q is selected from —OR 5 and —O—C(O)—R 5 and R 5 is a C 14-22 hydrocarbyl group having one double bond.

8. The ionic compound of claim 1 comprising a cation of the formula (Id):

wherein each of X—R 1 and Y—R 2 and Q is —O—(CH 2 ) 8 CH[Z]═CH(CH 2 ) 7 CH 3 or —O—C(O)—(CH 2 ) 7 CH[Z]═CH(CH 2 ) 7 CH 3 ; and

m is an integer from 2 to 5.

9. The ionic compound of claim 1 , wherein each of X—R 1 and Y—R 2 are the same and are —O—(CH 2 ) 8 CH[Z]═CH(CH 2 )CH 3 or —O—C(O)—(CH 2 ) 7 CH[Z]═CH(CH 2 ) 7 CH 3 , Q is selected from —O—(CH 2 ) 8 CH[Z]═CH(CH 2 ) 7 CH 3 or —O—C(O)—(CH 2 ) 7 CH[Z]═CH(CH 2 ) 7 CH 3 , and m is 3 or 4.

10. A non-viral transfection complex that comprises (i) a ionic compound as defined in claim 1 and a nucleic acid.

11. A non-viral transfection complex of claim 10 that further comprises (iii) a polycationic nucleic acid-binding component and (iv) a cell surface receptor binding component.

12. A pharmaceutical composition which comprises a transfection complex of claim 10 in admixture or conjunction with a pharmaceutically suitable carrier.

13. A vaccine comprising the transfection complex of claim 10 .