Abstract: Provided is a method for easily and efficiently producing encapsulated substance vesicles wherein a substance is encapsulated in the cavity of vesicles obtained by polymer self-assembly. Empty vesicles that have membranes comprising a first polymer that is a block copolymer with uncharged hydrophilic segments and a first kind of charged segments and a second polymer with a second kind of charged segments that carry a charge that is the opposite of said first kind of charged segments as well as spaces that are enclosed by said membranes are mixed in an aqueous medium with the substance that is to be encapsulated in the spaces.

Abstract: Provided is a method for easily and efficiently producing encapsulated substance vesicles wherein a substance is encapsulated in the cavity of vesicles obtained by polymer self-assembly. Empty vesicles that have membranes comprising a first polymer that is a block copolymer with uncharged hydrophilic segments and a first kind of charged segments and a second polymer with a second kind of charged segments that carry a charge that is the opposite of said first kind of charged segments as well as spaces that are enclosed by said membranes are mixed in an aqueous medium with the substance that is to be encapsulated in the spaces.

Abstract: Provided is a method for easily and efficiently producing encapsulated substance vesicles wherein a substance is encapsulated in the cavity of vesicles obtained by polymer self-assembly. Empty vesicles that have membranes comprising a first polymer that is a block copolymer with uncharged hydrophilic segments and a first kind of charged segments and a second polymer with a second kind of charged segments that carry a charge that is the opposite of said first kind of charged segments as well as spaces that are enclosed by said membranes are mixed in an aqueous medium with the substance that is to be encapsulated in the spaces.

Abstract: Disclosed is a polymer composite (polyplex) that contains nucleic acid, a cationic polymer, and an anionic polymer. The anionic polymer covers the surface of the composite comprising the cationic polymer and nucleic acid, has a negative charge at neutral pH, and can change so as to have a positive charge at mildly acidic pH.

Abstract: Disclosed is a polymer composite (polyplex) that contains nucleic acid, a cationic polymer, and an anionic polymer. The anionic polymer covers the surface of the composite comprising the cationic polymer and nucleic acid, has a negative charge at neutral pH, and can change so as to have a positive charge at mildly acidic pH.

Abstract: Provided are a delivery system that is useful in delivering a double-stranded ribonucleic acid that functions in gene silencing in glomeruli, particularly in mesangial cells and the like, to the tissue or cells, and the like. A polyion complex in the form of a non-polymeric micelle consisting of a double-stranded ribonucleic acid and a block copolymer represented by the formula (I) or (II) below, which are electrostatically bound together, wherein the polyion complex has an average particle diameter of less than 100 nm as measured by a dynamic light scattering measuring method: wherein each symbol is as defined in the specification.

Abstract: Provided is a method for easily and efficiently producing encapsulated substance vesicles wherein a substance is encapsulated in the cavity of vesicles obtained by polymer self-assembly. Empty vesicles that have membranes comprising a first polymer that is a block copolymer with uncharged hydrophilic segments and a first kind of charged segments and a second polymer with a second kind of charged segments that carry a charge that is the opposite of said first kind of charged segments as well as spaces that are enclosed by said membranes are mixed in an aqueous medium with the substance that is to be encapsulated in the spaces.

Abstract: Provided are a delivery system that is useful in delivering a double-stranded ribonucleic acid that functions in gene silencing in glomeruli, particularly in mesangial cells and the like, to the tissue or cells, and the like. A polyion complex in the form of a non-polymeric micelle consisting of a double-stranded ribonucleic acid and a block copolymer represented by the formula (I) or (II) below, which are electrostatically bound together, wherein the polyion complex has an average particle diameter of less than 100 nm as measured by a dynamic light scattering measuring method: wherein each symbol is as defined in the specification.

Abstract: Disclosed is a polymer composite (polyplex) that contains nucleic acid, a cationic polymer, and an anionic polymer. The anionic polymer covers the surface of the composite comprising the cationic polymer and nucleic acid, has a negative charge at neutral pH, and can change so as to have a positive charge at mildly acidic pH.