title: An Efficient, Regioselective Pathway to Cationic and Zwitterionic N-Heterocyclic Cellulose Ionomers.
abstract: Cationic derivatives of cellulose and other polysaccharides are attractive targets for biomedical applications due to their propensity for electrostatically binding with anionic biomolecules, such as nucleic acids and certain proteins. To date, however, relatively few practical synthetic methods have been described for their preparation. Herein, we report a useful and efficient strategy for cationic cellulose ester salt preparation by the reaction of 6-bromo-6-deoxycellulose acetate with pyridine or 1-methylimidazole. Dimethyl sulfoxide solvent favored this displacement reaction to produce cationic cellulose acetate derivatives, resulting in high degrees of substitution (DS) exclusively at the C-6 position. These cationic cellulose derivatives bearing substantial, permanent positive charge exhibit surprising thermal stability, dissolve readily in water, and bind strongly with a hydrophilic and anionic surface, supporting their potential for a variety of applications such as permeation enhancement, mucoadhesion, and gene or drug delivery. Expanding upon this chemistry, we reacted a 6-imidazolyl-6-deoxycellulose derivative with 1,3-propane sultone to demonstrate the potential for further elaboration to regioselectively substituted zwitterionic cellulose derivatives.
authors.affiliation: Department of Chemistry, ‡Department of Sustainable Biomaterials, and the §Macromolecules and Interfaces Institute, Virginia Tech , 230 Cheatham Hall, Blacksburg, Virginia 24061, United States.
authors.forename: Shu
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Chemistry, ‡Department of Sustainable Biomaterials, and the §Macromolecules and Interfaces Institute, Virginia Tech , 230 Cheatham Hall, Blacksburg, Virginia 24061, United States.
authors.forename: Jianzhao
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemistry, ‡Department of Sustainable Biomaterials, and the §Macromolecules and Interfaces Institute, Virginia Tech , 230 Cheatham Hall, Blacksburg, Virginia 24061, United States.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Esker
authors.affiliation: Department of Chemistry, ‡Department of Sustainable Biomaterials, and the §Macromolecules and Interfaces Institute, Virginia Tech , 230 Cheatham Hall, Blacksburg, Virginia 24061, United States.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Edgar
mesh_terms: D000107:Acetylation; D002412:Cations; D002482:Cellulose / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D054879:Halogenation; D006571:Heterocyclic Compounds / Q000138:chemical synthesis; D007093:Imidazoles / Q000737:chemistry; D007700:Kinetics; D011725:Pyridines / Q000737:chemistry
chemical_list: D002412:Cations; D006571:Heterocyclic Compounds; D007093:Imidazoles; D011725:Pyridines; C005062:acetylcellulose; D002482:Cellulose; C018100:1-methylimidazole