Abstract: The present invention provides a cationic lipid that can be used as a nucleic acid delivery carrier with good intracellular dynamics, a lipid membrane structure containing the same, a nucleic acid-introducing agent and a pharmaceutical composition containing any of them, a method for introducing nucleic acid into cells or target cells, and a method for producing a cell medicine. A cationic lipid represented by the formula (1) (definitions of symbols in the formula are as described in the specification), a lipid membrane structure using the aforementioned cationic lipid, a nucleic acid-introducing agent and a pharmaceutical composition using the aforementioned cationic lipid or the aforementioned lipid membrane structure, a method for introducing nucleic acid into cells or target cells by using the aforementioned nucleic acid-introducing agent, and a method for producing a cell medicine by using the aforementioned nucleic acid-introducing agent.

Abstract: The present invention provides a method for producing nucleic acid-encapsulated lipid nanoparticles, which can encapsulate any nucleic acid with high efficiency and with ease. A method for producing nucleic acid-encapsulated lipid nanoparticles, including the following steps: a) a step of preparing a suspension of lipid nanoparticles not containing a nucleic acid, by mixing an alcohol solution containing ionic lipid, sterol and PEG lipid with an acidic buffer having a buffering action at pH 1 to 6.5, and b) a step of mixing, without lyophilization, the suspension of the lipid nanoparticles obtained in step a with an aqueous solution containing a nucleic acid and optionally containing 0 to 25 v/v % alcohol, and optionally incubating the mixture at 0 to 95° C. for 0 to 60 min to obtain nucleic acid-encapsulated lipid nanoparticles.

Abstract: The present invention provides lipid nanoparticles for delivering nucleic acid to peripheral blood mononuclear cells that can improve the efficiency of nucleic acid delivery to peripheral blood mononuclear cells, and a method for delivering nucleic acid to peripheral blood mononuclear cells by using same. Lipid nanoparticles for use in delivering a nucleic acid to a peripheral blood mononuclear cell, containing an ionic lipid represented by the formula (1), a phospholipid that is 1,2-diacyl-sn-glycero-3-phosphocholine in which the acyl groups have not less than 20 carbon atoms and at least one of the acyl groups is an alkenoyl group, cholesterol, and a dimyristoylglycerol PEG represented by the formula: CH2(OR6)—CH(OR7)—CH2(OR8) (symbols in the formula are as described in the specification), and a method for delivering a nucleic acids to a peripheral blood mononuclear cell by using same.

Abstract: The present invention provides a lipid nanoparticle used for delivering a nucleic acid to a lymphatic endothelial cell, including an ionic lipid represented by the formula (1), cholesterol, and a dimyristoylglycerol PEG with a number average molecular weight of PEG chain of 1,000 to 3,000, wherein an amount of the dimyristoylglycerol PEG is not less than 3 mol % with respect to the total of the ionic lipid represented by the formula (1) and the cholesterol (the symbols in the formula (1) are as defined in the specification).

Abstract: The present invention provides a lipid nanoparticle including an ionic lipid represented by the following formula (1) wherein the symbols are as defined in the specification and an activated PEG lipid-bonded ligand having cell directivity.

Abstract: The present invention provides a lipid nanoparticle used for delivering a nucleic acid to a brain tissue, including an ionic lipid represented by the formula (1), phospholipid, cholesterol, and a dimyristoylglycerol PEG with a number average molecular weight of PEG chain of 4,000 to 6,000, wherein an amount of the dimyristoylglycerol PEG is 1 to 6 mol % with respect to the total of the ionic lipid represented by the formula (1), the phospholipid, and the cholesterol (the symbols in the formula (1) are as defined in the specification).

Abstract: The invention provides a cationic lipid, a lipid membrane structure containing same, and use thereof. The cationic lipid is represented by the formula (1) wherein R1a, R1b, R2a, R2b, R3a, R3b, Xa, Xb, Ya, Yb, Za, and Zb are as defined in the specification.

Abstract: The present invention provides, a cationic lipid represented by the formula (1) (wherein each symbol is as defined in the specification), a lipid membrane structure using the aforementioned cationic lipid, a nucleic acid-introducing agent using the aforementioned cationic lipid, and a method for introducing a nucleic acid by using the aforementioned nucleic acid-introducing agent.

Abstract: A lyophilized composition capable of encapsulating any nucleic acid with high efficiency and easily is provided. A lyophilized composition of lipid nanoparticles not containing a nucleic acid but containing an ionic lipid, a sterol, a PEG lipid, an acidic buffer component that shows a buffering action at pH 1-6, and a cryoprotectant, wherein a weight ratio of the cryoprotectant and a total lipid is 10:1-1000:1.

Abstract: The invention provides a cationic lipid, a lipid membrane structure containing same, and use thereof. The cationic lipid is represented by the formula (1) wherein R1a, R1b, R2a, R2b, R3a, R3b, Xa, Xb, Yb, Za, and Zb are as defined in the specification.

Abstract: The invention provides a cationic lipid, a lipid membrane structure containing same, and use thereof. The cationic lipid is represented by the formula (1) wherein R1a, R1b, R2a, R2b, R3a, R3b, Xa, Xb, Ya, Yb, Za, and Zb are as defined in the specification.

Abstract: To provide a degradable polyethylene glycol derivative in which polyethylene glycol chains are linked by a disulfide linker capable of accurately controlling the degradation rate under different reductive environments in the living body, and whose division rate into a polyethylene glycol chain of low molecular weight in the living body is able to be accurately controlled. A degradable polyethylene glycol derivative represented by formula (1). R1, R2, R3 and R4 represent each independently a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, and at least one of R1, R2, R3 and R4 is the hydrocarbon group; P1 is a straight-chain or branched polyethylene glycol chain having a number of ethylene glycol units of 3 or more; P2 is a straight-chain polyethylene glycol chain having a number of ethylene glycol units of 3 or more; w is an integer of 1 to 8; u is an integer of 1 to 10; X1 is a chemically reactive functional group; and Z1, Z2 and Z3 are each independently a selected divalent spacer.

Abstract: The present invention provides an O/W type emulsion having a volume median diameter of not more than 100 nm and containing a compound represented by the formula (1) wherein Xa and Xb are each independently X1, X2 or a 1,4-piperazinediyl group; s is 1 or 2, R4 is an alkyl group having 1-6 carbon atoms, na and nb are each independently 0 or 1, R1a, R1b, R2a and R2b are each independently an alkylene group having 1-6 carbon atoms, Ya and Yb are each independently an ester bond, or the like, and R3a and R3b are each independently a liposoluble vitamin residue or the like.

Abstract: The present invention aims to provide a cationic lipid that can be used as a nucleic acid delivery carrier, a lipid membrane structure using a cationic lipid, a nucleic acid-introducing agent using a cationic lipid, and a method of achieving nucleic acid introduction by using a nucleic acid-introducing agent containing a cationic lipid. A lipid membrane structure containing a cationic lipid represented by the formula (1) wherein each symbol is as defined in the DESCRIPTION, is superior in the stability in blood and tumor accumulation property. A nucleic acid-introducing agent using the cationic lipid can achieve high nucleic acid delivery efficiency of nucleic acid to be delivered into the cytoplasm.

Abstract: The invention provides a cationic lipid capable of achieving higher intracellular delivery efficiency than conventional cationic lipids, when used as a lipid membrane structure which is a carrier for delivering functional nucleic acid. The cationic lipid is represented by the formula (1): wherein each symbol is as defined herein.

Abstract: The present invention relates to a compound represented by the formula (1) wherein Xa and Xb are each independently X1 or X2; s is 1 or 2, R4 is an alkyl group having 1-6 carbon atoms, na and nb are each independently 0 or 1, R1a and R1b are each independently an alkylene group having 1-6 carbon atoms, R2a and R2b are each independently an alkylene group having 1-6 carbon atoms, Ya and Yb are each independently an ester bond, an amide bond, a carbamate bond, an ether bond or a urea bond, and R3a and R3b are each independently a sterol residue, a liposoluble vitamin residue or an aliphatic hydrocarbon group having 12-22 carbon atoms, and use thereof.