title: Phenylboronic Acid Appended Pyrene-Based Low-Molecular-Weight Injectable Hydrogel: Glucose-Stimulated Insulin Release.
abstract: A pyrene-containing phenylboronic acid (PBA) functionalized low-molecular-weight hydrogelator was synthesized with the aim to develop glucose-sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8-12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL(-1) . The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π-π stacking, and van der Waals interactions are the key factors for the self-assembled gelation. The diol-sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose-responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose-induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin-loaded hydrogel showed thixotropic self-recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells.
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032 (India).
authors.forename: Deep
authors.initials: D
authors.lastname: Mandal
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032 (India).
authors.forename: Subhra Kanti
authors.initials: SK
authors.lastname: Mandal
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032 (India).
authors.forename: Moumita
authors.initials: M
authors.lastname: Ghosh
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032 (India). bcpkd@iacs.res.in.
authors.forename: Prasanta Kumar
authors.initials: PK
authors.lastname: Das
mesh_terms: D001897:Boronic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D005947:Glucose / Q000737:chemistry* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007267:Injections; D061385:Insulins / Q000737:chemistry* / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D011721:Pyrenes / Q000138:chemical synthesis* / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001897:Boronic Acids; D020100:Hydrogels; D061385:Insulins; D011721:Pyrenes; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C030984:pyrene; D005947:Glucose; C010686:benzeneboronic acid
keywords: glucose; hydrogels; phenylboronic acid; self-assembly; sensors