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.

MCM-41/chondroitin sulfate hybrid hydrogels with remarkable mechanical properties and superabsorption of methylene blue.

This paper describes the synthesis of hybrid hydrogels based on chondroitin sulfate (CS) and mesoporous silica (MCM-41). The combination of the CS network and surface-modified MCM-41 yields resilient hybrids with a high water absorption power and excellent capacity for the removal of methylene blue (MB). In this system, two types of solute transport mechanisms exist: absorption and adsorption. The effect of MCM-41 on the physical-chemical properties of the hydrogels was assessed over a wide pH scale, and the absorption kinetics and isotherms of MB were studied by theoretical models. The mechanical properties of the hydrogels, such as the modulus of elasticity, yield strength, modulus of resilience, and fracture toughness, were significantly improved. This hydrogel exhibited high performance for water absorption (4000 % beyond its initial weight) and removal of MB (3982 ± 123.6 mg g-1), while the pure hydrogel removed 2912 ± 163.8 mg g-1.

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.