title: Development of a new calcium sulphate-based composite using alginate and chemically modified chitosan for bone regeneration.
abstract: In this work we developed a novel calcium sulphate-based composite in which the hemihydrate calcium sulphate (CHS) can be encapsulated in a polymeric biodegradable and biocompatible matrix, in order to retain the structural integrity and decrease the bioresorption rate in bone regeneration applications. Two polymers were employed to realize this system: chitosan (Ch) and sodium alginate (Alg), both already widely used in biotechnological and biomedical applications. Chitosan was modified in order to obtain a water soluble polymer, the N-succinylchitosan (sCh). The reaction was performed with succinic anhydride in presence of pyridine and confirmed by FT-IR and NMR analyses. Finely ground Alg and sCh powders were mixed in different compositions with CHS and by adding water to the powder mixture it was obtained a mouldable paste that sets in few hours. Thermogravimetric analyses coupled with solvent extraction performed on the composite proved the alginate crosslinking in the presence of CHS. Mechanical studies carried out on composites of different compositions demonstrated that the blend of the two polymeric components causes a substantial synergistic reinforcement of composites. The presence of carboxylic groups on sCh chain in addition to those of alginate could enhance the chelating power of polysaccharide mixture. The results obtained with morphological analyses (SEM) further confirmed the hypotesis of the synergistic effect between alginate and N-succinylchitosan in presence of calcium sulphate. In vitro cytotoxicity tests proved that the developed system was not cytotoxic.
authors.affiliation: Department of Experimental Medicine, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy.
authors.forename: Giovanna Gomez
authors.initials: GG
authors.lastname: d'Ayala
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rosa
authors.forename: Paola
authors.initials: P
authors.lastname: Laurienzo
authors.forename: Mario
authors.initials: M
authors.lastname: Malinconico
mesh_terms: D016475:3T3 Cells; D000464:Alginates / Q000378:metabolism*; D000818:Animals; D001696:Biomechanical Phenomena; D001861:Bone Regeneration; D002133:Calcium Sulfate / Q000378:metabolism*; D016923:Cell Death; D002470:Cell Survival; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism*; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; C118639:N-succinyl-chitosan; D020723:Glucuronic Acid; D048271:Chitosan; D002133:Calcium Sulfate