Branched amphipathic block polymer and molecular aggregate and drug delivery system using same

Patent metadata

Field	Value
Publication number	US-9295734-B2
Application number	US-201214126803-A
Country	US
Kind code	B2
Filing date	Jun 22, 2012
Priority date	Jun 23, 2011
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

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.

First claim

The invention claimed is:

1. A branched-type amphiphilic block polymer comprising:
a branched hydrophilic block comprising sarcosine; and
a hydrophobic block comprising polylactic acid;
wherein the branched-type amphiphilic block polymer has a structure represented by the following formula (I):

wherein n1, n2 and n3 represent numbers whose sum is 3 to 200, m represents a number of 15 to 60, and R represents a hydrogen atom or an organic group.

2. The branched-type amphiphilic block polymer according to claim 1 , wherein a ratio of a total number of the sarcosine units contained in the hydrophilic block to a total number of the lactic acid units contained in the hydrophobic block is 0.05 or more and less than 1.8.

3. A molecular assembly comprising the branched-type amphiphilic block polymer according to claim 1 .

4. The molecular assembly according to claim 3 , further comprising a linear type amphiphilic block polymer comprising one polysarcosine chain as a hydrophilic block and one polylactic acid chain as a hydrophobic block.

5. The molecular assembly according to claim 3 , which encapsulates a functional substance selected from the group consisting of a signal agent and a drug.

6. The molecular assembly according to claim 5 , wherein the functional substance has a polylactic acid chain.

7. The molecular assembly according to claim 3 , whose particle size is 10 to 50 nm.

8. The molecular assembly according to claim 3 , which is obtained by a preparation method comprising the steps of:
preparing a solution, in a container, containing the branched-type amphiphilic block polymer in an organic solvent;
removing the organic solvent from the solution to obtain a film comprising the branched-type amphiphilic block polymer on an inner wall of the container; and
adding water or an aqueous solution into the container and performing ultrasonic treatment to convert the film into a molecular assembly, thereby obtaining a dispersion liquid of the molecular assembly.

9. The molecular assembly according to claim 3 , which is obtained by a preparation method comprising the steps of:
preparing a solution, in a container, containing the branched-type amphiphilic block polymer in an organic solvent;
dispersing the solution into water or an aqueous solution; and
removing the organic solvent.

10. A drug delivery system comprising the molecular assembly according to claim 5 .

Assignees

• Ozeki Eiichi
• Kimura Shunsaku
• Makino Akira
• Shimadzu Corp
• Univ Kyoto

Inventors

• Ozeki Eiichi
• Kimura Shunsaku
• Makino Akira

Classifications

• A61K49/0082

  micelle, e.g. phospholipidic micelle and polymeric micelle · CPC title

• C08G69/44

  Polyester-amides · CPC title

• C08G83/008

  Supramolecular polymers · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C08L101/005

  Dendritic macromolecules · CPC title