Cationic oil-in-water emulsions
This invention generally relates to cationic oil-in-water emulsions that can be used to deliver negatively charged molecules, such as an RNA molecule. The emulsion particles comprise an oil core and a cationic lipid. The cationic lipid can interact with the negatively charged molecule thereby anchoring the molecule to the emulsion particles. The cationic emulsions described herein are particularly suitable for delivering nucleic acid molecules (such as an RNA molecule encoding an antigen) to cells and formulating nucleic acid-based vaccines.
1. A composition comprising an RNA molecule complexed with a particle of a cationic oil-in-water emulsion,
wherein the particle comprises (a) an oil core that is in liquid phase at 25° C., and (b) a cationic lipid, such that the overall net charge of the emulsion particle prior to RNA complexation is positive, and
wherein said RNA molecule is a self-replicating RNA that encodes a protein antigen and said RNA is anchored to the surface of said particle by non-covalent interactions;
wherein, when administered in an effective amount to a mammal, the composition elicits antibody titers to the antigen equal to or greater than the self-replicating RNA administered to the mammal not complexed with the particle.
2. The composition of claim 1 , wherein the particle further comprises a surfactant.
3. The composition of claim 2 , wherein the surfactant is a nonionic surfactant.
4. The composition of claim 3 , wherein the surfactant is sorbtian trioleate, polysorbate 80, or a combination thereof.
5. The composition of claim 3 , wherein the cationic oil-in-water emulsion comprises from about 0.01% to about 2.5% (v/v) nonionic surfactant.
6. The composition of claim 1 , wherein the composition comprises from about 0.2% to about 9% (v/v) of said oil.
7. The composition of claim 1 , wherein the oil core comprises Soybean oil, Sunflower oil, Olive oil, Squalene, Squalane or combinations thereof.
8. The composition of claim 1 , wherein the cationic lipid is selected from the group consisting of: 1,2-dioleoyloxy-3-(trimethylammonio)propane (DOTAP), 3β-[N—(N′,N′-Dimethylaminoethane)-carbamoyl]Cholesterol (DC Cholesterol), dimethyldioctadecylammonium (DDA), 1,2-Dimyristoyl-3-TrimethylAmmoniumPropane (DMTAP), dipalmitoyl(C 16:0 )trimethyl ammonium propane (DPTAP), distearoyltrimethylammonium propane (DSTAP), N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA), N,N-dioleoyl-N,N-dimethylammonium chloride (DODAC), 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (DOEPC), and 1,2-dioleoyl-3-dimethylammonium-propane (DODAP), 1,2-dilinoleyloxy-3-dimethylaminopropane (DLinDMA).
9. The composition of claim 1 , wherein the cationic lipid is 1,2-dioleoyloxy-3-(trimethylammonio)propane (DOTAP).
10. The composition of claim 9 , wherein the cationic oil-in-water emulsion comprises from about 0.5 mg/ml to about 5 mg/ml DOTAP.
11. The composition of claim 1 , wherein the cationic lipid is 313-[N—(N′,N′-Dimethylaminoethane)-carbamoyl]Cholesterol (DC Cholesterol) or dimethyldioctadecylammonium (DDA).
12. The composition of claim 11 , wherein the composition comprises from about 0.1 mg/ml to about 5 mg/ml DC Cholesterol or DDA.
13. The composition of claim 1 , wherein the cationic lipid is N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA), 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (DOEPC), or N,N-dioleoyl-N,N-dimethylammonium chloride (DODAC).
14. The composition of claim 13 , wherein the composition comprises from about 0.5 mg/ml to about 5 mg/ml DOTMA, DOEPC, or DODAC.
15. The composition of claim 1 , wherein the cationic oil-in-water emulsion further comprises a polymer or a surfactant in the aqueous phase of the emulsion.
16. The composition of claim 15 , wherein the polymer is a poloxamer, which is present at from about 0.1% to about 10% (v/v).
17. The composition of claim 1 , wherein the average diameter of the emulsion particles is from about 80 nm to about 180 nm, and the N/P ratio of the emulsion is at least 4:1.
18. The composition of claim 1 , wherein the composition is buffered and has a pH of about 6.0 to about 8.0.
19. The composition of claim 18 , wherein the pH is about 6.2 to about 6.8.
20. The composition of claim 17 , wherein the composition further comprises an inorganic salt, and the concentration of inorganic salt is no greater than 30 mM.
21. The composition of claim 1 , wherein the composition further comprises a nonionic tonicifying agent.
22. The composition of claim 21 , wherein the nonionic tonicifying agent is selected from the group consisting of a sugar, a sugar alcohol and combinations thereof.
23. The composition of claim 22 , wherein the nonionic tonicifying agent is present in a concentration of about 280 mM to about 300 mM.
24. The composition of claim 21 , wherein the composition is isotonic.
25. A method of generating an immune response in a subject, comprising administering to a subject in need thereof a therapeutically effective amount of the composition of claim 1 .
26. A composition comprising an RNA molecule complexed with a particle of a cationic oil-in-water emulsion, wherein the particle comprises (a) an oil core that is in liquid phase at 25° C., and (b) a cationic lipid, such that the overall net charge of the emulsion particle prior to RNA complexation is positive, and
wherein said RNA molecule is a self-replicating RNA that encodes a protein antigen and said RNA is anchored to the surface of said particle by non-covalent interactions, wherein, when administered in an effective amount to a mammal, the composition elicits antibody titers to the antigen equal to or greater than the self-replicating RNA administered to the mammal: i) not complexed with the particle and ii) at a 10-fold higher concentration, relative to the complexed RNA.
27. A composition comprising an RNA molecule complexed with a particle of a cationic oil-in-water emulsion,
wherein the particle comprises: (a) 0.2-10% (v/v) squalene core that is in liquid phase at 25° C., (b) 0.5-5.0 mg/ml of a cationic lipid, such that the overall net charge of the emulsion particle prior to RNA complexation is positive, (c) 0.01-2.5% (v/v) of a non-ionic surfactant and
wherein said RNA molecule is a self-replicating RNA that encodes a protein antigen and said RNA is anchored to the surface of said particle by non-covalent interactions;
wherein, when administered in an effective amount to a mammal, the composition elicits antibody titers to the antigen equal to or greater than the self-replicating RNA administered to the mammal not complexed with the particle.
28. The composition of claim 27 , wherein the cationic lipid is selected from 1,2-dioleoyloxy-3-(trimethylammonio)propane (DOTAP), 3β-[N(N′,N′-Dimethylaminoethane)-carbamoyl]Cholesterol (DC Cholesterol), dimethyldioctadecylammonium (DDA), 1,2-Dimyristoyl-3-TrimethylAmmoniumPropane (DMTAP), dipalmitoyl(C 16:0 )trimethyl ammonium propane (DPTAP), N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA), N,N-dioleoyl-N,N-dimethylammonium chloride (DODAC), 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (DOEPC), 1,2-dioleoyl-3-dimethylammonium-propane (DODAP), 1,2-dilinoleyloxy-3-dimethylaminopropane (DLinDMA), or a combination of the foregoing.
29. The composition of claim 28 , wherein the cationic lipid is selected from DOTAP, DDA, DC cholesterol, or a combination thereof.
30. The composition of claim 29 , wherein the non-ionic surfactant is selected from polysorbate 80, sorbitan trioleate, or a combination thereof.
31. The composition of claim 30 , wherein, when administered in an effective amount to a mammal, the composition elicits antibody titers to the antigen equal to or greater than the self-replicating RNA administered to the mammal: i) not complexed with the particle and ii) at a 10-fold higher concentration, relative to the complexed RNA.
32. The composition of claim 31 , wherein the cationic lipid is DOTAP.