Abstract: A lipid membrane structure encapsulating an siRNA inside thereof and containing a lipid compound of the formula (I) as a lipid component (R1 and R2 represent CH3—(CH2)n—CH?CH—CH2—CH?CH—(CH2)m—, n represents an integer of 3 to 5, m represents an integer of 6 to 10, p represents an integer of 2 to 7, and R3 and R4 represent a C1-4 alkyl group or a C2-4 alkenyl group.

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: A lipid membrane structure encapsulating an siRNA inside thereof and containing a lipid compound of the formula (I) as a lipid component (R1 and R2 represent CH3—(CH2)n—CH?CH—CH2—CH?CH—(CH2)m—, n represents an integer of 3 to 5, m represents an integer of 6 to 10, p represents an integer of 2 to 7, and R3 and R4 represent a C1-4 alkyl group or a C2-4 alkenyl group.

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.

Abstract: The present invention provides a liposome having excellent lung migration ability that had not existed hitherto, by including GALA or Chol-GALA in the liposome. Furthermore, by using the liposome, a pulmonary delivery carrier having a stronger knockdown effect of siRNA when compared to existing carriers is provided.

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.

Abstract: The present invention provides a liposome having excellent lung migration ability that had not existed hitherto, by including GALA or Chol-GALA in the liposome. Furthermore, by using the liposome, a pulmonary delivery carrier having a stronger knockdown effect of siRNA when compared to existing carriers is provided.

Abstract: A lipid membrane structure for delivering a substance to a target cell having satisfactory cell permeability, selectivity for target cell, and in vivo stability, wherein lipid membrane is modified with (a) a polyalkylene glycol bound with a target cell-selective ligand; and (b) a polypeptide comprising a plurality of arginine residues.

Abstract: A phospholipid derivative useful for the preparation of liposomes for efficient uptake of an antitumor agent or a gene intracellularly by a target tumor cell, which comprises a residue of an alcohol compound and a residue of a phospholipid, and comprising a peptide between the residue of an alcohol compound and the residue of a phospholipid, and wherein (a) the alcohol compound is an alcohol compound selected from poly(alkylene glycols) and the like, (b) the phospholipid is a phospholipid selected from phosphatidylethanolamines, phosphatidylcholines, phosphatidylserines and the like, and (c) the peptide is a peptide comprising a substrate peptide that can serve as a substrate of a matrix metalloproteinase, provided that one amino acid residue or an oligopeptide containing 2 to 8 amino acid residues may bind to one or both ends of the substrate peptide.