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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 self-assembling process. Ge-Pred was characterized by proton nuclear magnetic resonance spectra (H-1-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 zeta-potential. The average size of the nanohydrogels was about 300 nm and their zeta-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

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In the present study, mechanical and protein delivery properties of a system based on the interpenetration of calcium-alginate (Ca-Alg) and dextran-methacrylate (Dex-MA) networks are shown. Interpenetrated hydrogels beads were prepared by means of the alginate chains crosslinking with calcium ions, followed by the exposure to UV light that allows the Dex-MA network formation. Optical microscope analysis showed an average diameter of the IPN beads (Ca-Alg/Dex-MA) of 2 mm. This dimension was smaller than that of Ca-Alg beads because of the Dex-MA presence. Moreover, the strength of the IPN beads, and of their corresponding hydrogels, was influenced by the Dex-MA concentration and the crosslinking time. Model proteins (BSA and HRP) were successfully entrapped into the beads and released at a controlled rate, modulated by changing the Dex-MA concentration. The enzymatic activity of HRP released from the beads was maintained. These novel IPN beads have great potential as protein delivery system.