title: Biomimetic chitosan-calcium phosphate composites with potential applications as bone substitutes: preparation and characterization.
abstract: A novel biomimetic technique for obtaining chitosan-calcium phosphates (Cs-CP) scaffolds are presented: calcium phosphates are precipitated from its precursors, CaCl(2) and NaH(2) PO(4) on the Cs matrix, under physiological conditions (human body temperature and body fluid pH; 37°C and pH = 7.2, respectively). Materials composition and structure have been confirmed by various techniques: elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). FTIR and SEM data have shown the arrangement of the calcium phosphates-hydroxyapatite (CP-Hap) onto Cs matrix. In this case the polymer is acting as glue, bonding the calcium phosphates crystals. Behavior in biological simulated fluids (phosphate buffer solution-PBS and PBS-albumin) revealed an important contribution of the chelation between -NH3(+) and Ca(2+) on the scaffold interaction with aqueous mediums; increased quantities of chitosan in composites permit the interaction with human albumin and improve the retention of fluid. The composites are slightly degraded by the lysozyme which facilitates an in vivo degradation control of bone substitutes. Modulus of elasticity is strongly dependent of the ratio chitosan/calcium phosphates and recommends the obtained biomimetic composites as promising materials for a prospective bone application.
authors: Gh.Asachi' Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Department of Chemical-Physics, Iasi, Romania.
authors: Constantin E
authors: CE
authors: Tanase
authors: Marcel I
authors: MI
authors: Popa
authors: Liliana
authors: L
authors: Verestiuc
mesh_terms: D000418:Albumins / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009113:Muramidase / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D054457:Tissue Scaffolds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000418:Albumins; D018786:Bone Substitutes; D002130:Calcium Phosphates; D048271:Chitosan; C020243:calcium phosphate; D009113:Muramidase