Fabrication and properties of chitin/hydroxyapatite hybrid hydrogels as scaffold nano-materials

Novel hybrid hydrogels were prepared by introducing nano-hydroxyapatite (nHAp) into chitin solution dissolved in NaOH/urea aqueous solution at low temperature, and then by cross-linking with epichlorohydrin (ECH). Their structure and morphology were characterized by FTIR spectra, wide-angle X-ray diffraction (WAXD), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Our findings revealed that hydroxyapatite nano-particles were uniformly dispersed in chitin hydrogel networks. The chitin/nHAP hybrid hydrogel (Gel2) exhibited about 10 times higher mechanical properties (compressive strength: 274 kPa) than that of chitin hydrogel. Moreover, COS-7 cell culture experiment proved that cells could adhere and proliferate well on the chitin/nHAp hydrogels, suggesting good biocompatibility. All these results signified that these bio-materials could be potential candidates as scaffolds for tissue engineering.