Chitlac is a biocompatible modified polysaccharide composed of a chitosan backbone to which lactitol moieties have been chemically inserted via a reductive N-alkylation reaction with lactose. The physical-chemical and biological properties of Chitlac that have been already reported in the literature suggest a high accessibility of terminal galactose in the lactitol side chain. This finding may account for its biocompatibility which makes it extremely interesting for the production of biomaterials. The average structure and the dynamics of the side chains of Chitlac have been studied by means of NMR (nuclear Overhauser effect and nuclear relaxation) and molecular dynamics to ascertain this hypothesis. A complete assignment of the 1H and 13C NMR signals of the modified polysaccharide has been accomplished together with the determination of the apparent pKa values of the primary and secondary amines (6.69 and 5.87, respectively). NMR and MD indicated a high mobility of Chitlac side chains with comparable average internuclear distances between the two techniques. It was found that the highly flexible lactitol side chain in Chitlac can adopt two distinct conformations differing in the orientation with respect to the polysaccharide chain: a folded conformation, with the galactose ring parallel to the main chain, and an extended conformation, where the lactitol points away from the chitosan backbone. In both cases, the side chain resulted to be highly hydrated and fully immersed in the solvent

Insight into the molecular properties of chitlac, a chitosan derivative for tissue engineering

COSLOVI, ANNA;FERUGLIO, LUIGI;PAOLETTI, SERGIO;DONATI, IVAN
2013

Abstract

Chitlac is a biocompatible modified polysaccharide composed of a chitosan backbone to which lactitol moieties have been chemically inserted via a reductive N-alkylation reaction with lactose. The physical-chemical and biological properties of Chitlac that have been already reported in the literature suggest a high accessibility of terminal galactose in the lactitol side chain. This finding may account for its biocompatibility which makes it extremely interesting for the production of biomaterials. The average structure and the dynamics of the side chains of Chitlac have been studied by means of NMR (nuclear Overhauser effect and nuclear relaxation) and molecular dynamics to ascertain this hypothesis. A complete assignment of the 1H and 13C NMR signals of the modified polysaccharide has been accomplished together with the determination of the apparent pKa values of the primary and secondary amines (6.69 and 5.87, respectively). NMR and MD indicated a high mobility of Chitlac side chains with comparable average internuclear distances between the two techniques. It was found that the highly flexible lactitol side chain in Chitlac can adopt two distinct conformations differing in the orientation with respect to the polysaccharide chain: a folded conformation, with the galactose ring parallel to the main chain, and an extended conformation, where the lactitol points away from the chitosan backbone. In both cases, the side chain resulted to be highly hydrated and fully immersed in the solvent
JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2736093
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 7
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 26
social impact