Rheological characterization of novel carboxymethylated curdlan-silica hybrid hydrogels with tunable mechanical properties

The present work deals with a new type of hybrid polysaccharide-silica hydrogel fabricated by the sol-gel process in which a completely water-soluble precursor of tetrakis-(2-hydroxyethyl) orthosilicates (THEOS) and a bio-compatible polysaccharide of carboxymethylated curdlan (CMCD) have been used. The kinetic gelation process, mechanical properties and morphological structures of hybrid silica hydrogels at different concentrations of CMCD and THEOS were investigated by dynamic rheology, compression testing and scanning electron microscopy. CMCD was found to be served as a catalyst and template in the sol-gel process of THEOS in water. The mechanical strength of the resulting silica gels was tunable by the modulation of either the concentration of CMCD or THEOS. Higher content of THEOS and CMCD resulted in stiffer gels. Due to the tunable mechanical property and good biocompatibility, these hybrid hydrogels are promising for the applications as drug release systems in biomedical fields.