title: Insight into the ionotropic gelation of chitosan using tripolyphosphate and pyrophosphate as cross-linkers.
abstract: Ionotropic gelation of chitosan by means of opposite charged ions represents an efficient alternative to covalent reticulation because of milder condition of use and, in general, higher biocompatibility of the resulting systems. In this work 90° light scattering (turbidimetry), circular dichroism (CD) and1H NMR measurements have been performed to study the interactions between the biopolymer and ionic cross-linkers tripolyphosphate (TPP) and pyrophosphate (PPi) in dilute solutions. Thereafter, a dialysis-based technique was exploited to fabricate tridimensional chitosan hydrogels based on both polyanions. Resulting matrices showed a different mechanical behavior because of their peculiar mesh-texture at micro/nano-scale: in the present contribution we demonstrate that TPP and PPi favor the formation of homogeneous and inhomogeneous systems, respectively. The different texture of networks could be exploited in future for the preparation of systems for the controlled release of molecules.
authors.affiliation: Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127 Trieste, Italy. Electronic address: psacco@units.it.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Sacco
authors.affiliation: Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127 Trieste, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Paoletti
authors.affiliation: Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127 Trieste, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Cok
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, I-34127 Trieste, Italy.
authors.forename: Fioretta
authors.initials: F
authors.lastname: Asaro
authors.affiliation: Department of Life Sciences, Cattinara University Hospital, University of Trieste, Strada di Fiume 447, I-34149 Trieste, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Abrami
authors.affiliation: Department of Engineering and Architecture, University of Trieste, Via Alfonso Valerio, 6/A I-34127 Trieste, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Grassi
authors.affiliation: Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127 Trieste, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Donati
mesh_terms: D048271:Chitosan / Q000737:chemistry; D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004058:Diffusion; D011756:Diphosphates / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D011122:Polyphosphates / Q000737:chemistry*; D012542:Scattering, Radiation; D012996:Solutions
chemical_list: D003432:Cross-Linking Reagents; D011756:Diphosphates; D005782:Gels; D020100:Hydrogels; D011122:Polyphosphates; D012996:Solutions; D048271:Chitosan; C005692:triphosphoric acid
keywords: Chitosan hydrogel; Ionotropic gelation; Tripolyphosphate/pyrophosphate