title: A thixotropic hydrogel from chemically cross-linked guar gum: synthesis, characterization and rheological behaviour.
abstract: Polysaccharide guar gum (GG) was cross-linked in an alkaline solution with polyethylene glycol diglycidyl ether (PEGDGE) to create a new hydrogel. The GG hydrogel was examined by FT-IR spectroscopy, AFM analysis and SEM analysis. The water uptake of the GG hydrogel was measured at different pHs, and rheological studies were performed to verify the thixotropic nature of the material. Rheological studies revealed the pseudoplastic behaviour of the GG hydrogel and its thixotropic nature. AFM analysis on a sample which was subjected to shear stress showed the presence of nanoparticles in the hydrogel. When the sample was left to settle, the gel surface returned to its original homogenous morphology. The thixotropic and injectable nature of the GG hydrogel suggest its possible use in biomedical applications.
authors.affiliation: CRISMA and Department of Chemical and Biosystems Sciences and Technologies, University of Siena, Siena, Italy. barbucci@unisi.it
authors.forename: Rolando
authors.initials: R
authors.lastname: Barbucci
authors.forename: Daniela
authors.initials: D
authors.lastname: Pasqui
authors.forename: Roberto
authors.initials: R
authors.lastname: Favaloro
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Panariello
mesh_terms: D002240:Carbohydrate Sequence; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004853:Epoxy Resins / Q000737:chemistry; D005685:Galactans / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis* / Q000737:chemistry; D008351:Mannans / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D053149:Plant Gums / Q000737:chemistry*; D012212:Rheology; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D004853:Epoxy Resins; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D014867:Water; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C035364:Quetol 651; C007894:guar gum