Abstract: Provided is a molecular assembly (for example, a polymeric micelle nanoparticle) which is capable of efficiently encapsulating a fat-soluble drug. A molecular assembly comprising: an amphiphilic block polymer A1 comprising a hydrophilic block having a sarcosine unit and a hydrophobic block having a lactic acid unit; a hydrophobic polymer A2 having a lactic acid unit; a fatty acid triglyceride; and a fat-soluble drug. Examples of the fat-soluble drug include miriplatin.

Abstract: Provided is a molecular assembly (for example, a polymeric micelle nanoparticle) which is capable of efficiently encapsulating a fat-soluble drug. A molecular assembly comprising: an amphiphilic block polymer A1 comprising a hydrophilic block having a sarcosine unit and a hydrophobic block having a lactic acid unit; a hydrophobic polymer A2 having a lactic acid unit; a fatty acid triglyceride; and a fat-soluble drug. Examples of the fat-soluble drug include miriplatin.

Abstract: The present invention provides a molecular assembly which is less likely to accumulate in tissue other than cancer tissue, is highly safe for a living body, and can be prepared by a simple and safe method and whose particle size can be easily controlled. The present invention provides a molecular imaging system and a molecular probe useful for the system, and a drug delivery system and a molecular probe useful for the system. The present invention provides a method for preparing molecular assembly, by which the particle size of molecular assembly having a signal group or a drug can be arbitrarily controlled in order to allow the molecular assembly to effectively accumulate in cancer tissue by utilizing EPR effect.

Abstract: [Problem] To provide a novel fluorescent nanoparticle imaging probe having a switching function (a function to quench a fluorescent dye in a blood component and emit fluorescence in a tumor or an inflamed site to be imaged).

Abstract: Provided is a polymeric micelle pharmaceutical preparation that can increase the ratio of contrast at tumor site to background contrast in a short period of time after administration of a lactosome and can suppress the ABC phenomenon so that the lactosome can be administered more than once within a short span. A branched-type amphiphilic block polymer comprising: a multi-branched hydrophilic block comprising sarcosine; and a hydrophobic block comprising polylactic acid. The branched-type amphiphilic block polymer, wherein the number of branches of the hydrophilic block is 3. A molecular assembly comprising the branched-type amphiphilic block polymer. The molecular assembly further comprising a linear type amphiphilic block polymer.

Abstract: The present invention provides a molecular assembly whose retention time in a target site is adjusted depending on the kind or purpose of a labeling agent or drug encapsulated therein, and a molecular assembly that can suppress the ABC phenomenon and that can be administered more than once within a short span.

Abstract: Provided is a polymeric micelle pharmaceutical preparation that can increase the ratio of contrast at tumor site to background contrast in a short period of time after administration of a lactosome and can suppress the ABC phenomenon so that the lactosome can be administered more than once within a short span. A branched-type amphiphilic block polymer comprising: a multi-branched hydrophilic block comprising sarcosine; and a hydrophobic block comprising polylactic acid. The branched-type amphiphilic block polymer, wherein the number of branches of the hydrophilic block is 3. A molecular assembly comprising the branched-type amphiphilic block polymer. The molecular assembly further comprising a linear type amphiphilic block polymer.

Abstract: The present invention provides a novel fluorescent nanoparticle imaging probe having a switching function (a function to quench a fluorescent dye during nanoparticle preparation, and emit fluorescence during imaging). A switching fluorescent nanoparticle probe comprising: a molecular assembly composed of an amphiphilic block polymer having a hydrophilic block chain and a hydrophobic block chain; and a fluorescent dye encapsulated in the molecular assembly, wherein (a) the hydrophilic block chain comprises, as an essential hydrophilic structural unit, a unit selected from a sarcosine unit and an alkylene oxide unit, (b) the hydrophobic block chain comprises, as an essential hydrophobic structural unit, a unit selected from the group consisting of an amino acid unit and a hydroxylic acid unit, and (c) the fluorescent dye is a cyanine compound represented by the formula (I): and two or more molecules of the fluorescent dye are encapsulated in the single molecular assembly.

Abstract: Provided is a polymeric micelle pharmaceutical preparation that can increase the ratio of contrast at tumor site to background contrast in a short period of time after administration of a lactosome and can suppress the ABC phenomenon so that the lactosome can be administered more than once within a short span. A branched-type amphiphilic block polymer comprising: a multi-branched hydrophilic block comprising sarcosine; and a hydrophobic block comprising polylactic acid. The branched-type amphiphilic block polymer, wherein the number of branches of the hydrophilic block is 3. A molecular assembly comprising the branched-type amphiphilic block polymer. The molecular assembly further comprising a linear type amphiphilic block polymer.

Abstract: The present invention provides a molecular assembly whose retention time in a target site is adjusted depending on the kind or purpose of a labeling agent or drug encapsulated therein, and a molecular assembly that can suppress the ABC phenomenon and that can be administered more than once within a short span.

Abstract: The present invention provides a novel amphiphilic substance, a nanoparticle using the novel amphiphilic substance, which can be used as a nanocarrier having high biocompatibility, a drug delivery system and a probe useful for the system, and, a molecular imaging system and a probe useful for the system. An amphiphilic block polymer comprising a hydrophilic block; and a hydrophobic block, wherein the hydrophilic block is a hydrophilic polypeptide chain having 10 or more sarcosine units, and the hydrophobic block is a hydrophobic molecular chain comprising units selected from the group consisting of amino acid units and hydroxyl acid units as essential structural units, and having 5 or more of the essential structural units.

Abstract: The present invention provides a therapeutic system that is widely applicable to general solid cancers, can achieve both a reduction in side effects of cancer therapy and suppression of cancer recurrence and metastasis, and requires no expensive drug such as an antibody; and a nanoparticle for internal radiation therapy. A system for internal radiation therapy of a vascular lesion site comprising: a device comprising a means for acquiring image data showing a position of a vascular lesion site, and a means for positioning a needle, which should be punctured into the vascular lesion site, at the vascular lesion site based on the image data; and a nanoparticle comprising an amphiphilic block polymer comprising a hydrophilic block having a sarcosine unit and a hydrophobic block having a lactic acid unit, and a substance labeled with a ?-ray emitting nuclide. The nanoparticle for internal radiation therapy.

Abstract: Provided is a polymeric micelle pharmaceutical preparation that can increase the ratio of contrast at tumor site to background contrast in a short period of time after administration of a lactosome and can suppress the ABC phenomenon so that the lactosome can be administered more than once within a short span. A branched-type amphiphilic block polymer comprising: a multi-branched hydrophilic block comprising sarcosine; and a hydrophobic block comprising polylactic acid. The branched-type amphiphilic block polymer, wherein the number of branches of the hydrophilic block is 3. A molecular assembly comprising the branched-type amphiphilic block polymer. The molecular assembly further comprising a linear type amphiphilic block polymer.

Abstract: [Problem] To provide a novel fluorescent nanoparticle imaging probe having a switching function (a function to quench a fluorescent dye in a blood component and emit fluorescence in a tumor or an inflamed site to be imaged).

Abstract: The present invention provides a novel fluorescent nanoparticle imaging probe having a switching function (a function to quench a fluorescent dye during nanoparticle preparation, and emit fluorescence during imaging). A switching fluorescent nanoparticle probe comprising: a molecular assembly composed of an amphiphilic block polymer having a hydrophilic block chain and a hydrophobic block chain; and a fluorescent dye encapsulated in the molecular assembly, wherein (a) the hydrophilic block chain comprises, as an essential hydrophilic structural unit, a unit selected from a sarcosine unit and an alkylene oxide unit, (b) the hydrophobic block chain comprises, as an essential hydrophobic structural unit, a unit selected from the group consisting of an amino acid unit and a hydroxylic acid unit, and (c) the fluorescent dye is a cyanine compound represented by the formula (I): and two or more molecules of the fluorescent dye are encapsulated in the single molecular assembly.

Abstract: The present invention provides a molecular assembly which is less likely to accumulate in tissue other than cancer tissue, is highly safe for a living body, and can be prepared by a simple and safe method and whose particle size can be easily controlled. The present invention provides a molecular imaging system and a molecular probe useful for the system, and a drug delivery system and a molecular probe useful for the system. The present invention provides a method for preparing molecular assembly, by which the particle size of molecular assembly having a signal group or a drug can be arbitrarily controlled in order to allow the molecular assembly to effectively accumulate in cancer tissue by utilizing EPR effect.

Abstract: The present invention provides a novel amphiphilic substance, a nanoparticle using the novel amphiphilic substance, which can be used as a nanocarrier having high biocompatibility, a drug delivery system and a probe useful for the system, and, a molecular imaging system and a probe useful for the system. An amphiphilic block polymer comprising a hydrophilic block; and a hydrophobic block, wherein the hydrophilic block is a hydrophilic polypeptide chain having 10 or more sarcosine units, and the hydrophobic block is a hydrophobic molecular chain comprising units selected from the group consisting of amino acid units and hydroxyl acid units as essential structural units, and having 5 or more of the essential structural units.