Title
Insight into the Ionotropic Gelation of Chitosan using Tripolyphosphate and Pyrophosphate as cross-linkers
Author
Pasquale Sacco, Sergio Paoletti, Michela Cok, Fioretta Asaro, Michela Abrami, Mario Grassi, Ivan Donati
Year
2016
Journal
International Journal of Biological Macromolecules
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) and 1H 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.
Instrument
J-700
Keywords
Circular dichroism, Secondary structure, Ligand binding, Polymers, Biochemistry