Self-assembling and auto-crosslinkable hyaluronic acid hydrogels with a fibrillar structure

A hyaluronic acid derivative bearing pendant L-benzoyl-cysteine portions (with a derivatization degree equal to 10 mol.%) was synthesized by linking N,N'-dibenzoyl-L-cystine to the polysaccharide and then reducing its disulfide bridge to thiol groups. The formation of pi-pi stacking interactions between the benzoyl moieties was studied by fluorescence spectroscopy as a function of polymer concentration and oxidation time. The efficiency of oxidation of thiol groups to disulfide bridges occurring in phosphate buffer pH 7.4, was determined by colorimetric assays. The hydrogel formed by means of oxidative crosslinking has shown the presence of fibrillar aggregates as detected by light and scanning electron microscopy. Human derm fibroblasts were encapsulated into hydrogel-forming solution, and their ability to proliferate was tested during 3 days of culture.