Synthesis and application of layered double hydroxide-hosted 2-aminoterephthalate for the Knoevenagel condensation reaction

D-mannose functionalized MgAl-LDH/Fe-MOF nanocomposite as a new intelligent nanoplatform for MTX and DOX co-drug delivery

Commonly the directly administered chemotherapy drugs lack targeting in tumor treatment. Thus, trying to improve cancer treatment efficiency led us to design a new intelligent system for cancer treatment. Considering these, in the current work, at first, the 2-aminoterephthalic acid (NH₂-BDC) intercalated layered double hydroxides (MgAl-(NH₂-BDC) LDH) were synthesized simply. Afterward, the in situ growth of the iron-based metal-organic frameworks in the presence of MgAl-(NH₂-BDC) LDH occurred (MgAl-LDH/Fe-MOF). In the end, the reaction of MgAl-LDH/Fe-MOF with D-mannose (D-Man) achieved the MgAl-LDH/Fe-MOF/D-Man ternary hybrid nanostructure. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis confirmed the formation of the monodisperse Fe-MOF with nanosize in the presence of MgAl-LDH. Importantly, methotrexate (MTX) and doxorubicin (DOX) entrapment efficiency reached respectively about 28 wt% and 21% for MgAl-LDH/Fe-MOF/D-Man. The in vitro drug release experiments revealed a higher drug release at pH 5.0 in comparison with pH 7.4 which revealed its promising potential for anticancer drug delivery applications. Bioassay results revealed that the co-drug-loaded MgAl-LDH/Fe-MOF/D-Man has higher cytotoxicity on MDA-MB 231 cells. At last, fluorescence microscopy and flow cytometric analysis confirmed the successful uptake of MgAl-LDH/Fe-MOF/D-Man into MDA-MB 231 cell lines, as well as its bioimaging potential. A survey in the published literature approved that this work is the first report on the evaluation of the MgAl-LDH/Fe-MOF/D-Man for targeted co-delivery of both MTX and DOX. Finally, results collectively demonstrate the importance of the biocompatible MgAl-LDH/Fe-MOF/D-Man as a hopeful candidate for biomedicinal applications from the targeted co-drug delivery and bioimaging potential viewpoints.

Ce-Containing MgAl-Layered Double Hydroxide-Graphene Oxide Hybrid Materials as Multifunctional Catalysts for Organic Transformations

The combination of layered double hydroxides (LDH) with graphene oxide (GO) enables the formation of nanohybrids with improved properties. This work focuses on the structural and catalytic properties of Ce-containing MgAl LDH-GO composites bearing different concentrations of GO in the range of 5-25 wt.%. The synthesis of the composites was performed by co-precipitating the LDH phase in the presence of GO, while their characterization was performed using XRF, XRD, DRIFT, Raman, SEM, nitrogen adsorption-desorption, and acidity-basicity measurements. The LDH-GO composites, showing redox, basic, and acid catalytic functions, were tested in two different types of organic transformations: (i) Knoevenagel condensation and (ii) one-pot cascade oxidation-Knoevenagel condensation. (i) The cinnamic acid was synthesized by the Knoevenagel condensation of benzaldehyde with diethylmalonate. The composites showed catalytic performances in strong contrast to neat LDH or GO, suggesting a synergistic interaction between the two components. During Knoevenagel condensation, the catalytic activity increased with the GO content in the hybrids up to 15 wt.% and decreased afterwards. (ii) 2-Benzoyl-3-phenylacrylonitrile was synthesized by the aerobic oxidation of benzyl alcohol followed by the Knoevenagel condensation with benzoyl acetonitrile using three different non-polar solvents, i.e., toluene, benzene, and mesitylene. The conversion of benzyl alcohol was higher for the hybrid materials compared to the individual components but decreased with the increase of the graphene oxide concentration.