Abstract: A pH-responsive polymer formed of a biocompatible polymer to which a group which is electrically neutral under pH environments of more than 7 and which changes to be cationic at pH 7 or less is bonded.

Abstract: The present invention pertains to a ligand that contains a plurality of groups represented by formula (1) and is capable of multivalently binding to a glutamine transporter expressed in excess in a cancer cell compared to a normal cell.

Abstract: The present invention pertains to: a p-boronophenylalanine derivative that comprises a polymer to which a group represented by formula (I) is linked directly or via a linker; a composition containing same; and a kit for producing said derivative and composition.

Abstract: A bio-related substance bonded to a branched and degradable polyethylene glycol derivative that is degraded in the cells represented by the following formula (A): wherein each symbol is as defined in the present specification, is provided by the present invention.

Abstract: A complex is provided comprising a conjugate in which a polymer having a boronic acid group and a compound having a diol structure are bonded, and a substance that is complexed with the conjugate.

Abstract: A conjugate is provided in which a deferoxamine-type compound, which is at least one compound selected from the group consisting of deferoxamine or an ion or salt thereof, and a derivative thereof, and a biocompatible polymer are conjugated, where the biocompatible polymer contains a first biocompatible polymer chain and a second biocompatible polymer chain that is different from the first biocompatible polymer chain.

Abstract: The present invention is directed to provide antitumor agent including water-soluble sulfasalazine as an active ingredient. Antitumor agents were obtained with, as the water-soluble sulfasalazine, a PEG-modified sulfasalazine represented by the following formula: wherein an average value of n is 4 or larger and 1136 or smaller.

Abstract: An intracellularly degraded branched and degradable polyethylene glycol derivative represented by the following formula (1): wherein each symbol is as defined in the present specification, that is used for modifying bio-related substances is provided by the present invention.

Abstract: The present invention pertains to a ligand that contains a plurality of groups represented by formula (1) and is capable of multivalently binding to a glutamine transporter expressed in excess in a cancer cell compared to a normal cell.

Abstract: The invention provides a high-molecular-weight polyethylene glycol derivative that does not cause vacuolation of cells. The degradable polyethylene glycol derivative is represented by the following formula (1): wherein m is 1-7, n1 and n2 are each independently 45-682, p is 1-4, R is an alkyl group having 1-4 carbon atoms, Z is an oligopeptide with 2-8 residues composed of neutral amino acids excluding cysteine, Q is a residue of a compound having 2-5 active hydrogens, X is a functional group capable of reacting with a bio-related substance, and L1, L2, L3, L4 and L5 are each independently a single bond or a divalent spacer.

Abstract: The present invention pertains to: a p-boronophenylalanine derivative that comprises a polymer to which a group represented by formula (I) is linked directly or via a linker; a composition containing same; and a kit for producing said derivative and composition.

Abstract: The invention provides a bio-related substance bonded to a high-molecular-weight polyethylene glycol derivative that does not cause vacuolation of cells. The bio-related substance bonded to a degradable polyethylene glycol derivative is represented by the formula (A): wherein m is 1-7, n1 and n2 are each independently 45-682, p is 1-4, R is an alkyl group having 1-4 carbon atoms, Z is an oligopeptide with 2-8 residues composed of neutral amino acids excluding cysteine, Q is a residue of a compound having 2-5 active hydrogens, D is the bio-related substance, L1, L2, L3, L4 and L5 are each independently a single bond or a divalent spacer, and y is 1-40.

Abstract: The present invention is directed to provide antitumor agent including water-soluble sulfasalazine as an active ingredient. Antitumor agents were obtained with, as the water-soluble sulfasalazine, a PEG-modified sulfasalazine represented by the following formula: wherein an average value of n is 4 or larger and 1136 or smaller.

Abstract: A pH-responsive polymer formed of a biocompatible polymer to which a group which is electrically neutral under pH environments of more than 7 and which changes to be cationic at pH 7 or less is bonded.

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: 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.