Chitosan-Hydroxyapatite Composite Obtained by Biomimetic Method as New Bone Substitute

Chitosan-Hydroxyapatite (Cs-Hap) composites were prepared through a biomimetic method by Hap precipitation from its precursors, CaCl2 and NaH2PO4, on the chitosan fibres. Materials composition and structure have been analyzed by usual analytical techniques, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). FT-IR and SEM data have shown the formation of Hap onto Cs fibers and Cs acting as glue, bonding the Hap crystals. The Cs-Hap composites porosity, from SEM data analysis, increases by increasing the content of Hap. The biodegradation of materials was tested in buffered lysozyme solution and the degraded polysaccharide was measured; the SEM data, before and after degradation, revealed that composites morphology had not appreciable changed. ‘In vitro’ degradation studies indicate that these composite have slighter degradation rate which is coupled to the degree of N-deacetylation, hydrophilicity and crystallinity. Swelling properties measurements in simulated body fluids have shown that the swelling ratio of composites is decreased when the content of Hap is higher. The obtained results revealed that obtained Cs-Hap composites are promising materials as bone substitute due to their adequate swelling properties and controlled degradation rate.