Abstract: The purpose of the present invention is to provide an electrostatically bonded vesicle which bears disulfide bonds or thiol groups. The present invention relates to a vesicle having a membrane which is formed from both a first polymer of (a) or (b) and a second polymer of (c) or (d) (with the proviso that a combination of (b) and (d) is excepted) and in which the cationic segment and anionic segment of the polymers are partially crosslinked. First polymer: (a) a block copolymer (I) having both an electrically non-charged hydrophilic segment and a cationic segment, (b) an amino acid polymer (I) having a cationic segment. Second polymer: (c) a block copolymer (II) having both an electrically non-charged hydrophilic segment and an anionic segment, (d) an amino acid polymer (II) having an anionic segment.

Abstract: The present invention provides a protein delivery means (e.g., a polyion complex) which allows efficient introduction into cells (particularly into the cytoplasm), is highly stable in serum, and is also widely applicable. The polyion complex of the present invention comprises a cationic polymer having a polycation moiety and a charge-conversional protein whose overall charge is converted from basic or neutral to acidic by a specific charge regulator.

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: It is an object of the present invention to provide: a polyion complex that sufficiently retains a photosensitizing substance in serum and is excellent in terms of structural stability; a nucleic acid polyplex as a constituent thereof; and a device and a kit for delivering a nucleic acid into a cell. The nucleic acid polyplex of the present invention comprises a cationic polymer represented by general formula (1) and a nucleic acid. The polyion complex of the present invention comprises the nucleic acid polyplex of the present invention and an anionic photosensitizing substance.

Abstract: A unit structure-type pharmaceutical composition includes at least one nucleic acid, such as siRNA, electrostatically bound to at least one block copolymer having a cationic polyamino acid segment and a hydrophilic polymer chain segment. The negative charge(s) of the nucleic acid are counterbalanced, at least substantially, by the positive charge(s) of the cationic polyamino acid segment such that the pharmaceutical composition is electrically neutral or nearly electrically neutral. Further, the nucleic acid is covered with the hydrophilic polymer chain segment(s). The at least one block copolymer thereby improves the blood retention capability of the nucleic acid(s).

Abstract: The present invention provides a polymer-metal complex composite, which comprises a block copolymer capable of serving as a constituent member of a polymeric micelle and a metal complex having MRI contrast ability, accumulates in a tumor-specific manner, achieves high image contrast even in a small amount, and has reduced side effects and a long retention time in blood. The polymer-metal complex composite of the present invention comprises a block copolymer (A) represented by general formula (a) and a metal complex (B) having MRI contrast ability, wherein the composite comprises a structure in which a carboxyl anion of poly(carbo) in the copolymer (A) is attached to the metal complex (B) via a metal atom (M).

Abstract: A block copolymer includes a polyamino acid chain segment and a hydrophilic polymer chain segment. The polyamino acid chain segment includes at least one amino acid residue having a side chain that contains a cationic group and at least one amino acid residue having a side chain that contains a substituted phenylboronic acid group. In the substituted phenylboronic acid group, at least one hydrogen of the phenyl ring is substituted so that the phenylboronic acid group has a pKa of less than 8. Such a block copolymer serves as a carrier that simultaneously imparts stability to a biotechnology-based drug in blood and provides suitable drug-releasing properties of the drug at an affected area.

Abstract: A substrate surface on which either a substance to detect analyte or an analyte per se is immobilized, which surface is formed by a treatment of substrate surface with a liquid which contains uncrosslinked polymer based on polyethylene glycol chain segment, said treatment conducted either simultaneously with the immobilization of said substance or analyte or after said substance or analyte has been immobilized on said surface. The non-specific adsorption of impurity protein or the like which is co-existent in sample for assay is significantly restrained.

Abstract: Fine particles of crystalline polyol are provided having a cationic polymer fixed on the crystal surfaces. These fine particles can stably carry an anionically charged compound on their surfaces.

Abstract: A liquid composition containing a polymer micelle and having a pH values of 3.0 to 7.0 is provided. The micelle is constituted of a coordination compound having a block copolymer of polyethylene glycol and polyglutamic acid and cisplatin that is coordinate-bonded to the block copolymer.

Abstract: This invention provides organic-inorganic hybrid particles containing as the essential components a block copolymer comprising an uncharged hydrophilic polymer chain segment and a polymer chain segment containing a repeated structural unit having a carboxylate ion group at its side chain; calcium ion (Ca2+), phosphate ion (PO43?) or carbonate ion (CO32?), or a mixture of these anions; and a contrast agent. The particles provide, in particular, carriers for stably delivering an MRI contrast agent to a target site.

Abstract: The present invention provides a cationic polyamino acid suitable for a carrier that can form a stable complex with a nucleic acid under a physiological condition and release the nucleic acid in cells suitably. The cationic polyamino acid can associate with a nucleic acid and includes a cationic amino acid residue having a cationic group in a side chain and a hydrophobic amino acid residue having a hydrophobic group in a side chain. The cationic polyamino acid includes 1 to 20 units of the cationic amino acid residue and is represented by the following formula (1). The meaning of each symbol in the formula is as shown in the description.

Abstract: A substrate surface on which either a substance to detect analyte or an analyte per se is immobilized, which surface is formed by a treatment of substrate surface with a liquid which contains uncrosslinked polymer based on polyethylene glycol chain segment, said treatment conducted either simultaneously with the immobilization of said substance or analyte or after said substance or analyte has been immobilized on said surface. The non-specific adsorption of impurity protein or the like which is co-existent in sample for assay is significantly restrained.

Abstract: The present invention aims to provide a gene delivery system with higher safety and higher sustainability, which is effective for the treatment of ischemic diseases and the like, and the like. The present invention provides a pharmaceutical composition containing, as an active ingredient, a polyanionic substance that suppresses expression of PHD2, and containing a polyion complex of the polyanionic substance and a polycation chargeable polymer.

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: A composition of matter for use in encapsulating a drug is expressed by formula (1) or formula (2): wherein R1 and R2 are each independently a hydrogen atom or a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms; A is a hydrophilic polymer chain; L1 and L3 are each a linking group; B is a cation-containing group; R3 is a side chain of an amino acid; z is an integer of 5 to 500; x is an integer of 40% or more of z; y is 0 or a positive integer; z-x-y is 0 or a positive integer; p is an integer of 1 to 10; and q is an integer of 1 to 10.

Abstract: It is an object of the present invention to provide a polyion complex used as a non-viral gene vector, which achieves sufficiently high gene expression efficiency to a target cell. The polyion complex of the present invention comprises a block copolymer formed by binding polyethylene glycol to polycation via a disulfide group and a nucleic acid.

Abstract: The present invention provides an efficient delivery system for a nucleic acid, more specifically, a cationic poly(amino acid) that has a side chain having a plurality of different amine functional groups in a moiety including a cationic group and that has a hydrophobic group introduced into part of the side chain, and a polyion complex (PIC) of the poly(amino acid) and an oligo- or polynucleotide.

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: There are provided an anionic polymer, a polyion complex, and a ternary polymer composite, each of which is stable in a biological environment and is capable of realizing small RNA delivery without causing any undesired immune response. An anionic polymer according to an embodiment of the invention includes: a main chain which includes repeating units having carboxyl groups; and a side chain which is linked with part of the carboxyl groups in the main chain and is represented by the following formula: -A-B—X where: A represents a residue having one or more aminoethyl bonds; B represents an in vivo cleavable bond; and X represents a small RNA. A polyion complex according to an embodiment of the invention includes the anionic polymer as described above and a cationic polymer. A ternary polymer composite according to an embodiment of the invention includes the polyion complex as described above and a charge conversional polymer.