Sustained-release nucleic acid matrix compositions

1. A matrix composition comprising:

a. a biocompatible polymer in non-covalent association with a first lipid component comprising a sterol, wherein the moles of sterol constitute up to 40% of the moles of total lipids present;

b. a second lipid component comprising at least one phospholipid having fatty acid moieties of at least 14 carbons;

c. at least one nucleic acid based agent;

d. a linear polyethylene glycol (PEG) having a molecular weight in the range of 1,000-10,000; and

e. at least one cationic lipid;

wherein the matrix composition is substantially free of water, and is adapted for providing sustained and/or controlled release of the nucleic acid ingredient, wherein at least 30% of said agent is released from the composition at zero-order kinetics.

2. The matrix composition of claim 1 , wherein the sterol is cholesterol.

3. The matrix composition of claim 2 , wherein the cholesterol is present in an amount of 5-50 mole percent of the total lipid content of said matrix composition.

4. The matrix composition of claim 1 , wherein the phospholipid in the second lipid component is selected from the group consisting of phosphatidylcholine or a derivative thereof; a mixture of phosphatidylcholines or derivatives thereof; a phosphatidylethanolamine or a derivative thereof; and any combination thereof.

5. The matrix composition of claim 1 , wherein said cationic lipid is selected from the group consisting of DC-Cholesterol, 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), Dimethyldioctadecylammonium (DDAB), 1,2-dilauroyl-sn-glycero-3-ethylphosphocholine (Ethyl PC), 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA) and any combination thereof.

6. The matrix composition of claim 1 , wherein the biocompatible polymer is selected from the group consisting of a biodegradable polymer, a non-biodegradable polymer and any combination thereof.

7. The matrix composition of claim 6 , wherein the biodegradable polymer is a biodegradable polyester selected from the group consisting of PLA (polylactic acid), PGA (poly glycolic acid), PLGA (Poly (lactic co glycolic acid) and combinations thereof.

8. The matrix composition of claim 6 , wherein the non-biodegradable polymer is selected from the group consisting of PEG acrylate, PEG methacrylate, methylmethacrylate, ethylmethacrylate, butylmethacrylate, 2-ethylhexylmethacrylate, laurylmethacrylate, hydroxylethyl methacrylate, 2-methacryloyloxyethylphosphorylcholine (MPC), polystyrene, derivatized polystyrene, polylysine, poly N-ethyl-4-vinyl-pyridinium bromide, poly -methylacrylate, silicone, polyoxymethylene, polyurethane, polyamides, polypropylene, polyvinyl chloride, polymethacrylic acid and combination thereof.

9. The matrix composition of claim 6 , wherein the biocompatible polymer comprises a co-block copolymer of a biodegradable polymer and a non-biodegradable polymer.

10. The matrix composition of claim 1 , wherein the weight ratio of total lipids to the biodegradable polymer is between 1:1 and 9:1 inclusive.

11. The matrix composition of claim 1 , wherein said matrix composition is homogeneous.

12. The matrix composition of claim 1 , further comprising at least one compound selected from the group consisting of sphingolipid, tocopherol, a free fatty acid having 14 or more carbon atoms, a PEGylated lipid and an additional phospholipid selected from the group consisting of a phosphatidylserine, a phosphatidylglycerol, and a phosphatidylinositol.

13. The matrix composition of claim 1 wherein the nucleic acid based agent is selected from the group consisting of: plasmid DNA, linear DNA selected from poly and oligo-nucleotides, chromosomal DNA, messenger RNA (mRNA), antisense DNA/RNA, RNAi, siRNA, microRNA (miRNA), ribosomal RNA, oligonucleotide DNA (ODN) single and double strand, siRNA, CpG imunostimulating sequence (ISS), locked nucleic acid (LNA) and ribozyme.

14. The matrix composition of claim 1 , wherein said biocompatible polymer is a biodegradable polyester; and said phospholipid is a combination of a phosphatidylethanolamine having fatty acid moieties of at least 14 carbons and a phosphatidylcholine having fatty acid moieties of at least 14 carbons.

15. An implant comprising the matrix composition of claim 1 .

16. A pharmaceutical composition for administering a nucleic based agent to a subject in need thereof, comprising the matrix composition of claim 1 .

17. A method of administering a nucleic acid based agent to a subject in need thereof, said method comprising the step of administering to said subject a matrix composition according to claim 1 , thereby administering a nucleic acid based agent to a subject in need thereof.

18. A medical device, comprising: a substrate and a biocompatible coating deposited on at least a fraction of said substrate, wherein said biocompatible coating comprises the matrix composition of claim 1 .

19. The medical device of claim 18 , wherein said biocompatible coating includes multi-layers.

20. A method of producing the matrix composition of claim 1 comprising the steps of:

a. mixing into a first volatile organic solvent (i) a biocompatible polymer and (ii) a first lipid component comprising at least one lipid having a polar group;

b. mixing polyethylene glycol into a water-based solution of the nucleic acid agent;

c. mixing the solution obtained in step (b) with a second volatile organic solvent and a second lipid component comprising at least one phospholipid having fatty acid moieties of at least 14 carbons;

d. mixing the solutions obtained in steps (a) and (c) to form a homogeneous mixture; and

e. removing the volatile solvents and water,

thereby producing a homogeneous polymer-phospholipids matrix comprising the nucleic acid agent, wherein the matrix composition is substantially free of water, and is adapted for providing sustained and/or controlled release of said nucleic acid agent.

21. The method of claim 20 , wherein step (c) further comprises (i) removing the solvents by evaporation, freeze drying or centrifugation to form a sediment; and (ii) suspending the resulted sediment in the second volatile organic solvent.

22. The method of claim 20 wherein following step (d) the resulted solution is injected into liquid nitrogen, to water or hot air (spray drier) in order to produce vesicles or is inserted into a mold, and subsequently the liquids are removed in order to get a specific structured matrix.