Polysaccharide nanocrystals, such as the rod-like whiskers of cellulose and chitin, and platelet-like starch nanocrystals, were for the first time incorporated into supramolecular hydrogels based on cyclodextrin/polymer inclusion in order to enhance mechanical strength and regulate drug release behavior The structures and properties of the resultant nanocomposite hydrogels were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and rheological testing As expected, the elastic modulus of the nanocomposite hydrogels climbed, owing to the reinforcing function of the polysaccharide nanocrystals The modulus of the cellulose whisker-doped hydrogel was 50 times higher than that of the native hydrogel Furthermore, the presence of polysaccharide nanocrystals increased the stability of the hydrogel framework and inhibited the diffusion of bovine serum albumin, which served as a model protein drug in the nanocomposite hydrogels and showed prominent sustained release profiles Importantly, the incorporation of polysaccharide nanocrystals did not show additional cytotoxicity as comparison with the native hydrogel In addition, the inherited shear-thinning property of the nanocomposite hydrogels contributed to their potential as injectable biomaterials (C) 2010 Elsevier Ltd All rights reserved.