Physicochemical characterisation and thermal decomposition of synthetic collagen based nanocomposites in comparison with natural bone

Two collagen based nanocomposites were synthesised by initiating the reconstitution of collagen solutions in the absence or presence of alginate with simultaneous hydroxyapatite synthesis. The structural characteristics and thermal behaviours of both collagen-hydroxyapatite (M1) and collagen/alginate-hydroxyapatite (M2) were evaluated in comparison with rabbit bone (RB), which confirmed the bone-like features of synthetic nanocomposites. However, differences in microstructure, phase and composition were found among the respective samples calcined at 600 and 1000 degrees C, as revealed by X-ray diffraction and scanning electron microscopy. Especially, in contrast to the presence of beta tricalcium phosphate in M1, pure HA was obtained in both M2 and RB after calcination at 1000 degrees C, confirming that the introduction of alginate with Ca capturing capability is beneficial to achieve nanocomposites with better analogue to natural bone.