Self-assembled gellan-based nanohydrogels as a tool for prednisolone delivery

Self-assembled nanohydrogels based on hydrophobically modified polysaccharides have been extensively studied due to their wide potential applications as drug delivery systems. In the present study, we developed and characterized self-assembling nanohydrogels based on sonicated gellan gum chains. Prednisolone (Pred), a poorly water soluble anti-inflammatory drug, was chemically conjugated to the carboxylic groups of gellan (Ge-Pred) and it was the hydrophobic moiety responsible for the selfassembling process. Ge-Pred was characterized by proton nuclear magnetic resonance spectra (1H-NMR) and the cellular cytotoxicity was assessed by the MTS assay. The self-aggregation behavior in aqueous media of Ge-Pred was evaluated by the pyrene fluorescence technique and the nanohydrogels (NHs), prepared by bath sonication in water, were analyzed by dynamic light scattering (DLS) and z-potential. The average size of the nanohydrogels was about 300 nm and their z-potential values were negative. Our results showed that Ge-Pred NHs are cytocompatible, that the drug is bioavailable and, consequently, they represent an interesting and innovative carrier for prednisolone.