pH-sensitive polymeric compositions, kits, and methods

{
  "publication_number": "US10696769B2",
  "country": "US",
  "kind": "B2",
  "title": "pH-sensitive polymeric compositions, kits, and methods",
  "abstract": "Provided herein are polymeric compositions having a relaxation time that is a function of pH. The polymeric compositions can include an anionic monomer, a cationic monomer, and a crosslinker. The crosslinker may comprise at least one of a diacrylate crosslinker and a dimethacrylate crosslinker. Also provided herein are methods of pH sensing, and methods of forming a polymeric composition. Kits of parts also are provided that include a polymeric composition. The polymeric compositions may be used to determine the pH of one or more biological tissues and/or liquids.",
  "claims": [
    "1. A polymeric composition comprising: a crosslinked co-polymer comprising a cationic monomer, an anionic monomer, and a crosslinker; wherein the mol ratio of the cationic monomer to the anionic monomer is about 60:40, the cationic monomer comprises a side chain having a tertiary amine, the anionic monomer comprises a side chain having a carboxylic acid, the crosslinker comprises at least one of a diacrylate crosslinker and a dimethacrylate crosslinker, and the polymeric composition has a relaxation time that is a function of pH.",
    "2. The polymeric composition of claim 1, wherein the relaxation time of the polymeric composition is unique at each pH within a range of about 4.5 to about 8.",
    "3. The polymeric composition of claim 1, wherein the relaxation time of the polymeric composition is unique at each pH within a range of about 6 to about 8.",
    "4. The polymeric composition of claim 1, wherein the relaxation time of the polymeric composition is unique at each pH within a range of about 6 to about 7.5.",
    "5. The polymeric composition of claim 1, wherein the cationic monomer is a monomer of formula (I): wherein R 1 is selected from hydrogen or a monovalent C 1 hydrocarbyl, R 2 is selected from a divalent C 1 -C 6 hydrocarbyl, and R 3 and R 4 are independently selected from a C 1 -C 6 hydrocarbyl.",
    "6. The polymeric composition of claim 5, wherein R 1 is a monovalent unsubstituted C 1 hydrocarbyl, R 2 is a divalent unsubstituted C 1 -C 4 hydrocarbyl, and the cationic monomer is a monomer of formula (IA):",
    "7. The polymeric composition of claim 6, wherein each of R 3 and R 4, independently, is a monovalent unsubstituted C 1 -C 3 hydrocarbyl, and the cationic monomer is a monomer of formula (TB):",
    "8. The polymeric composition of claim 5, wherein R 1 is a monovalent unsubstituted C 1 hydrocarbyl, R 2 is a divalent unsubstituted C 2 hydrocarbyl, R 3 and R 4 are monovalent unsubstituted C 1 hydrocarbyls, and the cationic monomer is 2-(dimethylamino)ethyl methacrylate.",
    "9. The polymeric composition of claim 1, wherein the anionic monomer is a monomer of formula (II): wherein R 5 is a divalent C 1 -C 6 hydrocarbyl, R 6 is selected from hydrogen or a monovalent C 1 hydrocarbyl, and m is 0 or 1.",
    "10. The polymeric composition of claim 9, wherein m is 0, R 6 is hydrogen, and the anionic monomer is acrylic acid.",
    "11. The polymeric composition of claim 1, wherein the dimethacrylate crosslinker has a structure according to formula (III): wherein R 7 is a divalent Ci-C 6 hydrocarbyl.",
    "12. The polymeric composition of claim 11, wherein R 7 is a divalent unsubstituted C 2 hydrocarbyl, and the dimethacrylate crosslinker is ethylene glycol dimethacrylate.",
    "13. The polymeric composition of claim 1, wherein the diacrylate crosslinker has a structure according to formula (IV): wherein R 8 is a divalent C-C 6 hydrocarbyl.",
    "14. The polymeric composition of claim 13, wherein R 8 is a divalent unsubstituted C 2 hydrocarbyl, and the diacrylate crosslinker is ethylene glycol diacrylate.",
    "15. The polymeric composition of claim 1, wherein the relaxation time is a longitudinal relaxation time.",
    "16. The polymeric composition of claim 1, wherein the relaxation time is a transverse relaxation time.",
    "17. The method of claim 15, wherein curing the polymerizable composition comprises disposing the polymerizable composition in a curing vessel of a desired shape, and heating the polymerizable composition.",
    "18. The method of claim 15, further comprising shaping the polymeric composition.",
    "19. The method of claim 15, wherein the mixture further comprises water.",
    "20. A composition comprising: a first polymeric composition comprising a first crosslinked co-polymer comprising a first cationic monomer, a first anionic monomer, and a first crosslinker, wherein the first polymeric composition has a relaxation time that is a function of pH; and at least one of a second polymeric composition and at least one additional pH sensitive material.",
    "21. The composition of claim 20, wherein the relaxation time is unique at each pH within a range of about 4.5 to about 8.",
    "22. The composition of claim 20, wherein the relaxation time is unique at each pH within a range of about 6 to about 8.",
    "23. The composition of claim 20, wherein the relaxation time is a longitudinal relaxation time.",
    "24. The composition of claim 20, wherein the relaxation time is a transverse relaxation time.",
    "25. The composition of claim 20, wherein the composition comprises the first polymeric composition and the second polymeric composition, and the first polymeric composition and the second polymeric composition have maximum relaxation times that occur at different pH values.",
    "26. The composition of claim 20, wherein the composition comprises the first polymeric composition and the at least one additional pH sensitive material, and the first polymeric composition and the at least one additional pH sensitive material have maximum relaxation times that occur at different pH values.",
    "27. The composition of claim 20, wherein the second polymeric composition comprises a second crosslinked co-polymer comprising a second cationic monomer, a second anionic monomer, and a second crosslinker; and the second crosslinked co-polymer has a relaxation time that is a function of pH.",
    "28. The composition of claim 20, wherein the relaxation time of the second polymeric composition is unique at each pH within a range of about 4.5 to about 8.",
    "29. The composition of claim 20, wherein the first polymeric composition and the second polymeric composition and/or the at least one additional pH sensitive material are in a particulate form, and the composition comprises a mixture of particles.",
    "30. The composition of claim 29, wherein the mixture of particles is measured in a single voxel, and the relaxation times of the first polymeric composition and the second polymeric composition and/or the at least one additional pH sensitive material are determined with a multi-exponential fitting.",
    "31. The composition of claim 20, wherein the at least one additional pH sensitive material comprises p-HEMA.",
    "32. A sensor comprising the composition of claim 20, wherein the sensor is a two compartment sensor, and the first polymeric composition is disposed on and/or in a first compartment of the sensor, and the second polymeric composition or the at least one additional pH sensitive material is disposed on and/or in a second compartment of the sensor."
  ],
  "description_excerpt": "This invention was made with government support under grant number 5-U54-CA151884 awarded by the National Institutes of Health. The government has certain rights in the invention.\n\nSeveral pH-sensitive hydrogels are known, such as those that include poly-hydroxyethylmethacrylate (p-HEMA) crosslinked with N,N′-methylenebisacrylamide (BIS). p-HEMA-BIS hydrogels have been used as sensors, because the transverse relaxation time (T 2) of the p-HEMA-BIS hydrogels can depend on the pH of the environments in which the hydrogels are disposed.\n\nPlots of the pH versus the T 2 relaxation time of the p-HEMA-BIS hydrogels, however, have revealed that the relaxation time may peak at about pH 6.5. The peak, therefore, occurs within several preferred detection ranges, including detection ranges that are physiologically relevant.\n\nAs a result, a single T 2 relaxation time can correspond to two, non-peak pH values, thereby imparting ambiguity to the results provided by the p-HEMA-BIS hydrogels. For example, if a T 2 relaxation time of about 200 ms corresponds to the peak pH of about 6.5, then a T 2 relaxation time of about 150 ms may correspond to an off-peak pH of about 6 and an off-peak pH of about 7.5.\n\nThere remains a need for a pH-sensitive polymeric compositions having relaxation times that correspond to a single pH value within preferred detection ranges.\n\nProvided herein are polymeric compositions having a relaxation time that is a function of pH. In one embodiment, the relaxation time of the polymeric composition is unique at each pH within a range of about 4.5 to about 8.",
  "cpc": [
    "C08F 220/06",
    "A61B 5/14507",
    "A61B 5/14539",
    "A61B 5/1468",
    "A61B 5/4848",
    "C08F 220/34",
    "C08F 222/102",
    "C08F 2800/20",
    "C08L 33/14",
    "G01N 33/84"
  ],
  "ipc": [
    "C08F 220/06",
    "C08F 220/34",
    "G01N 33/84",
    "A61B 5/00",
    "A61B 5/145",
    "A61B 5/1468",
    "C08L 33/14"
  ],
  "assignees": [
    "Massachusetts Institute of Technology"
  ],
  "inventors": [
    "Gregory James Ekchian",
    "Michael John Cima"
  ],
  "filing_date": "2016-12-01",
  "publication_date": "2020-06-30",
  "grant_date": "2020-06-30",
  "priority_date": "2015-12-01",
  "application_number": "US-201615366740-A",
  "family_id": "57750555",
  "cited_by_count": 1,
  "citations": [
    "US4906717A",
    "WO2000047111A1",
    "US6307372B1",
    "US6751491B2",
    "US20040248326A1",
    "EP1647283A1",
    "EP1716870A1",
    "US20130233093A1",
    "WO2015055727A1"
  ]
}