title: Synthesis and characterization of phosphorylcholine-substituted chitosans soluble in physiological pH conditions.
abstract: A polymer analogous synthesis involving the reductive amination of phosphorylcholine (PC)-glyceraldehyde with primary amines of deacetylated chitosan (M(w) approximately 57000 g mol(-1)) was used to prepare phosphorylcholine-substituted chitosans (PC-CH) with a degree of substitution (DS) ranging from approximately 11 to approximately 53 mol % PC-substituted glucosamine residues. The PC-CH derivatives were characterized by (1)H NMR spectroscopy, FTIR spectroscopy, and multiangle laser light scattering gel permeation chromatography (MALLS-GPC). The pK(a) of the PC-substituted amine groups (pK(a) approximately 7.20) was determined by (1)H NMR titration. The PC-CH samples (1.0 g L(-1)) were shown to be nontoxic using an MTT assay performed with human KB cells. Aqueous solutions of PC-CH samples (4.0 g L(-1)) of DS >or= 22 mol % PC-substituted glucosamine residues remained clear, independently of pH (4.0 < pH < 11.0). The remarkable water solubility and nontoxicity displayed by the new PC-CH samples open up new opportunities in the design of chitosan-based biomaterials and nanoparticles.
authors.affiliation: Departamento de Química e Ciências Ambientais, UNESP-Universidade Estadual Paulista, São José do Rio Preto, Brazil.
authors.forename: Marcio J
authors.initials: MJ
authors.lastname: Tiera
authors.forename: Xing-Ping
authors.initials: XP
authors.lastname: Qiu
authors.forename: Sofiane
authors.initials: S
authors.lastname: Bechaouch
authors.forename: Qin
authors.initials: Q
authors.lastname: Shi
authors.forename: Júlio C
authors.initials: JC
authors.lastname: Fernandes
authors.forename: Françoise M
authors.initials: FM
authors.lastname: Winnik
mesh_terms: D000107:Acetylation; D002240:Carbohydrate Sequence; D048271:Chitosan / Q000138:chemical synthesis* / Q000737:chemistry; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010767:Phosphorylcholine / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010767:Phosphorylcholine; D048271:Chitosan