Lipid derivative for nucleic acid introduction
An object is to provide a lipid particle that is not positively charged at a pH of the body fluid (typically in the neutral range), and that enables efficient onset of the effect of a medicinal substance encapsulated in the lipid particle; and to provide a lipid for forming the lipid particle. The object is achieved by the phospholipid represented by formula (1), and a lipid particle containing the phospholipid: wherein R 1 and R 2 are identical or different, and represent a chain hydrocarbon group, m represents 1 or 2, n represents 1 or 2, and p represents an integer of 1 to 4.
1. A phospholipid represented by formula (1):
wherein R 1 and R 2 are identical or different, and represent a chain hydrocarbon group, m represents 1 or 2, n represents 1 or 2, and p represents an integer of 1 to 4.
2. The phospholipid according to claim 1 , wherein the chain hydrocarbon group is an unsaturated chain hydrocarbon group.
3. The phospholipid according to claim 1 , wherein the chain hydrocarbon group has 12 to 24 carbon atoms.
4. The phospholipid according to claim 1 , wherein m and n are both 2.
5. The phospholipid according to claim 1 , wherein p is 1 or 2.
6. A lipid particle comprising the phospholipid of claim 1 , the phospholipid being a first phospholipid.
7. The lipid particle according to claim 6 , in which a polynucleotide is encapsulated.
8. The lipid particle according to claim 6 , further comprising cholesterol.
9. The lipid particle according to claim 6 , further comprising a second phospholipid, the second phospholipid being a phosphatidylcholine, wherein the first phospholipid has an unsaturated chain hydrocarbon group.
10. The lipid particle according to claim 9 , wherein the second phospholipid is present in an amount of 30 to 70 mol, per 100 mol of the first phospholipid.
11. A method for producing a lipid particle, the method comprising mixing an alcohol solution containing the phospholipid of claim 1 with an acid aqueous solution containing a water-soluble polynucleotide.
12. The method according to claim 11 , wherein the alcohol solution contains butanol as a solvent.
13. A medical drug comprising a lipid particle containing the phospholipid of claim 1 , and a polynucleotide.