title: Physico-chemical and structural properties of hydrogels formed by chitosan, in the presence and absence of poly(vinylpyrrolidone) and sodium decylsulfate.
abstract: The structure of chemically-crosslinked chitosan and chitosan-poly(vinylpyrrolidone) (PVP) hydrogels is investigated by means of the combined use of small-angle neutron scattering (SANS), electron paramagnetic resonance spectroscopy (EPR), intradiffusion, and swelling degree measurements. These hydrogels may be described in terms of an inhomogeneous structure composed by polymer-rich and polymer-poor regions. The polymer-rich regions, whose correlation distance zeta is ranged between approximately 600 and approximately 850 A, are, in turn, characterized by the presence of a network formed by the chemical crosslinks, with a mean correlation distance xi approximately 90 A. The structures of chitosan and chitosan-PVP hydrogels have also been analyzed in the presence of sodium decylsulfate micelles that could provide a multidomain system useful, in principle, for drug delivery applications. Both SANS and EPR measurements show that sodium decylsulfate micelles do not significantly interact with both the gels. Finally, intradiffusion and swelling degree measurements show an improved hydrophilicity of chitosan-PVP gels, even further magnified by the presence of C10OS surfactant.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Napoli "Federico II", Via Cinthia, 80126 Naples, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Mangiapia
authors.forename: Henrich
authors.initials: H
authors.lastname: Frielinghaus
authors.forename: Gerardino
authors.initials: G
authors.lastname: D'Errico
authors.forename: Ornella
authors.initials: O
authors.lastname: Ortona
authors.forename: Roberto
authors.initials: R
authors.lastname: Sartorio
authors.forename: Luigi
authors.initials: L
authors.lastname: Paduano
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D020100:Hydrogels; D009502:Neutrons; D011205:Povidone / Q000737:chemistry*; D053838:Scattering, Small Angle; D013451:Sulfonic Acids / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D013451:Sulfonic Acids; D048271:Chitosan; D011205:Povidone; C517619:sodium decylsulfonate