Synthesis of resilient hybrid hydrogels using UiO-66 MOFs and alginate (hydroMOFs) and their effect on mechanical and matter transport properties.

Herein, we report the preparation of an organic-inorganic hybrid hydrogel architecture using vinyl alginate and UiO-66 MOFs (metal-organic frameworks) modified with acrylic acid (AA) UiO-66AA. UiO-66 MOFs with different crystal sizes (600, 1500, and 2500 nm) were synthesized and the effect on the mechanical and transport properties of the resulting materials, such as water absorption capacity and drug release, were evaluated. HydroMOF showed higher water absorption capacity than the pure hydrogel and enhanced mechanical properties, which depend on crystal size and the amount of UiO-66AA MOF used. The initial release rate of drug (burst release) from hydroMOFs was lower when small-sized crystals or a small amount of large-sized crystals were used; thus these are essential in changing half-life values of release rates. Finally, the cytotoxicity screening successfully showed that hydroMOFs are promising biocompatible compounds proven to have the advantages of minimized burst release and mechanical robustness.

Cerium catalyst promoted C-S cross-coupling: synthesis of thioethers, dapsone and RN-18 precursors.

In this work, we present a novel, efficient and green methodology for the synthesis of thioethers by the C-S cross-coupling reaction with the assistance of [Ce(l-Pro)2]2Ox as a heterogeneous catalyst in good to excellent yields. A scale-up of the protocol was explored using an unpublished methodology for the synthesis of a dapsone-precursor, which proved to be very effective over a short time. The catalyst [Ce(l-Pro)2]2Ox was recovered and it was shown to be effective for five more reaction cycles.

Bionanocomposites based on mesoporous silica and alginate for enhanced drug delivery.

This work reports the preparation, the characterization and the prednisolone release profile of biocompatible hydrogel nanocomposites containing mesoporous silica (SBA) and alginate as a biomaterial for enhanced drug delivery with reduced burst effect and improved mechanical properties. Such systems, which were prepared using specific SBA/alginate-crosslinking chemistry, exhibited interconnecting pore hybrid network owing to both mesoporous silica and hydrogel characteristics. Activated SBA was shown to be a determinant factor in inhibiting initial burst by nearly 90% and the drug was released with minimal burst kinetics. The nanoparticles reduced the movements of polymer chains, affecting macromolecular relaxation, and the distribution of mesoporous silica within the hydrogel made drug release into surrounding liquid less favorable. The proposed systems are biocompatible with human immortalized RWPE-1 prostatic epithelial cells. This report offers an approach of up-to-date interest for the development of advanced biomaterials for further physiological and pathological applications.