# US 11,027,026 B2 · Polymer, and contrast agent for photoacoustic imaging, including the polymer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,026 B2 - Document ID: US11027026B2 - Status: Granted - Kind: B2 - Application number: 15/511,898 - Filed: 2015-10-16 - Published: 2018-08-16 - Granted: 2021-06-08 - Earliest claimed: 2014-10-16 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Hideo Saji; Kohei Sano; Akira Makino; Kengo Kanazaki; Fumio Yamauchi; Satoshi Ogawa - Web page: https://patentgrep.com/patent/US11027026B2 ## CPC - A61K 49/0034: {Indocyanine green, i.e. ICG, cardiogreen} - A61K 49/0054: {Macromolecular compounds, i.e. oligomers, polymers, dendrimers} - C08G 73/0233: {Polyamines derived from (poly)oxazolines, (poly)oxazines or having pendant acyl groups} - G01N 33/575: for cancer - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract To provide a polymer having a high tumor/blood ratio. The present invention provides a polymer represented by the following formula (P1): wherein in the formula (P1), R0 represents any of a residue or a functional group derived from a cationic polymerization initiator; L represents a linker and L may not be present; n represents an integer of 1 or more; D represents a dye backbone of a dye having absorption in the near-infrared region. ## Claims ### Claim 1 A polymer represented by formula (A1): wherein in the formula (A1), R0 represents a residue derived from a cationic polymerization initiator, or a functional group; L1 represents a linker and L1 may not be present; D1 is represented by formula (d1-1); and Z1 represents a structure comprising at least one unit represented by formula (A2), at least one unit represented by formula (A3), and at least one unit represented by formula (A4): wherein in the formula (A2), D2 is represented by the formula (d1-1); and R1 to R4 each independently represents a hydrogen atom, or a substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms, in which, when a substituent is present, the substituent is a functional group including at least one selected from the group consisting of a halogen atom, an oxygen atom and a nitrogen atom; wherein in the formula (A3), R1 to R4 each independently represents a hydrogen atom, or a substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms, in which, when a substituent is present, the substituent is a functional group including at least one selected from the group consisting of a halogen atom, an oxygen atom, and a nitrogen atom; and R5 represents any of a methyl group, an ethyl group, an isopropyl group, a n-propyl group, a n-butyl group, a n-octyl group, a n-heptyl group, a phenyl group, a butenyl group, and a pentynyl group; wherein in the formula (A4), R1 to R4 each independently represents a hydrogen atom, or a substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms, in which, when a substituent is present, the substituent is a functional group including at least one selected from the group consisting of a halogen atom, an oxygen atom, and a nitrogen atom, and wherein a ratio of a unit represented by the formula (A4) to repeating units of the polymer is 12.6% or less as measured by electric conductivity: wherein, in the formula (d1-1), * represents binding to L1 in the formula (A1) or represents binding to Z1 in the formula (A1) when L1 is not present. ### Claim 2 (depends on 1) The polymer according to claim 1, wherein the polymer is a random copolymer having the unit represented by the formula (A2) and the unit represented by the formula (A3). ### Claim 3 (depends on 1) The polymer according to claim 1, wherein a ratio of the unit represented by the formula (A2) to repeating units carried by the polymer is 60% or less. ### Claim 4 (depends on 1) The polymer according to claim 1, wherein a ratio of the unit represented by the formula (A2) to repeating units carried by the polymer is 0.01% to 10%. ### Claim 5 (depends on 1) The polymer according to claim 1, wherein each of R1 to R4 is a hydrogen atom. ### Claim 6 (depends on 1) The polymer according to claim 1, wherein L1 has a structure represented by any of formulas (11) to (114): wherein in the formulas (11) to (114), two * represent direct binding or indirect binding to D1 and Z1, respectively, in the formula (A1); and in the formula (114), ω represents a residue derived from a terminal after completion of cationic polymerization reaction, or a functional group. ### Claim 7 (depends on 1) The polymer according to claim 1, wherein R5 is an ethyl group. ### Claim 8 (depends on 1) The polymer according to claim 1, wherein a molecular weight of the polymer is 10000 to 200000, as measured by Gel Permeation Chromatography. ### Claim 9 (depends on 1) The polymer according to claim 1, wherein a molecular weight of the polymer is 10000 to 50000, as measured by Gel Permeation Chromatography. ### Claim 10 (depends on 1) The polymer according to claim 1, wherein R0 is selected from a functional group derived from any of a dye, a reporter molecule, a target-binding molecule, and a polymer. ### Claim 11 (depends on 1) A contrast agent for photoacoustic imaging, comprising the polymer according to claim 1, and a dispersion medium. ### Claim 12 (depends on 1) The polymer according to claim 1, wherein R5 is the isopropyl group. ### Claim 13 (depends on 1) The polymer according to claim 1, wherein a number of bound dye per polymer molecule is 1.9 to 7.8. ### Claim 14 (depends on 13) The polymer according to claim 13, wherein the number of bound dye per polymer molecule is 4.7 to 7.8.