FLUORESCENCE STUDY OF MICROVISCOSITY OF HYALURONAN HYDROGELS CONTAINING HYDROPHOBIC NANODOMAINS DURING FOURTEEN DAYS OF AGEING

This paper deals with the fluorescence study of microviscosity changes of hydrogel composed by hyaluronan and cationic surfactant cetyltrimethylammonium bromide (CTAB) during fortnight-ageing. The steady state anisotropy values obtained in the experiments were used to estimate the microviscosity of the corresponding hydrogel regions. Two different fluorescent probes were used, perylene for hydrophobic domains and rhodamine 6G for hydrophilic region. It is observed that the microviscosity in the hydrophobic domains of hydrogel is roughly constant, indicating that these domains do not undergo significant structural changes during ageing. However, the microviscosity of hydrophilic parts gradually decreases, which indicates structural changes in the nearby area of rhodamine molecules.