title: Hydrogen-bonding-induced chain folding and vesicular assembly of an amphiphilic polyurethane.
abstract: We have reported synthesis and vesicular assembly of a novel amphiphilic polyurethane with hydrophobic backbone and hydrophilic pendant carboxylic acid groups which were periodically grafted to the backbone via a tertiary amine group. In aqueous medium the polymer chain adopted a folded conformation which was stabilized by intrachain H-bonding among the urethane groups. Such a model was supported by concentration and solvent-dependent FT-IR, powder XRD, and urea-mediated "denaturation" experiments. Folded polymer chains further formed vesicular assembly which was probed by dynamic light scattering, TEM, AFM, SEM, and fluorescence microscopic studies, and dye encapsulation experiments. pH-dependent DLS and fluorescence microscopic studies revealed stable polymersome in entire tested pH window of 3.5-11.0. Zeta potential measurements showed a negatively charged surface in basic pH while a charge-neutral surface in neutral and acidic pH. MTT assay with CHO cell line indicated good cell viability.
authors.affiliation: Polymer Science Unit, Indian Association for the Cultivation of Science, Kolkata 700032, India.
authors.forename: Tathagata
authors.initials: T
authors.lastname: Mondal
authors.forename: Krishna
authors.initials: K
authors.lastname: Dan
authors.forename: Jolly
authors.initials: J
authors.lastname: Deb
authors.forename: Siddhartha S
authors.initials: SS
authors.lastname: Jana
authors.forename: Suhrit
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000494:pharmacology; D016466:CHO Cells; D002264:Carboxylic Acids / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D003412:Cricetulus; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D008968:Molecular Conformation; D011140:Polyurethanes / Q000138:chemical synthesis* / Q000494:pharmacology; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D014867:Water
chemical_list: D001672:Biocompatible Materials; D002264:Carboxylic Acids; D011140:Polyurethanes; D013501:Surface-Active Agents; D014867:Water