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The high porosity and versatile composition of the benchmarked mesoporous metal (Fe, Al, Cr) trimesate metal–organic frameworks (MIL-100(Fe, Al, Cr)) make them very promising solids in different strategic industrial and societal domains (separation, catalysis, biomedicine, etc.). In particular, MIL-100(Fe) nanoparticles (NPs) have been recently revealed to be one of the most promising and innovative next generation tools enabling multidrug delivery to overcome cancer resistance. Here, we analyzed the in vitro toxicity of the potential drug nanocarrier MIL-100(Fe) NPs and the effect of the constitutive cation by comparing its cytotoxicity with that one of its Cr and Al analogue NPs. Lung (A549 and Calu-3) and hepatic (HepG2 and Hep3B) cell lines were selected considering pulmonary, ingestion or intravenous exposure modes. First, the complete physicochemical characterization (structural, chemical and colloidal stability) of the MIL-100(Fe, Al, Cr) NPs was performed in the cell culture media. Then, their cytotoxicity was evaluated in the four selected cell lines using a combination of methods from cell impedance, cell survival/death and ROS generation to DNA damage for measuring genotoxicity. Thus, MIL-100(Fe, Al, Cr) NPs did not induce in vitro cell toxicity, even at high doses in the p53 wild type cell lines (A549 and calu-3 (lung) and HepG2 (liver)). The only toxic effect of MIL100-Fe was observed in the hepatocarcinoma cell line Hep3B, which is stress sensitive because it does not express TP53, the guardian of the genome.

Controlled-sized crystals, from the nano to the microscale, of the biocompatible and highly stable porous iron(III) 3,3,′5,5′-azobenzenetetracarboxylate MIL-127(Fe) MOF have been successfully prepared with very high space-time-yields using different synthetic routes.

The mesomorphic behavior, shape shifting, and shape-memory types of two homologous series of main-chain liquid-crystalline co-elastomers (MC-LCEs) with composition-tunable transition temperatures and mesophases structures are reported. The weakly cross-linked macromolecules were prepared in a one-step procedure by the versatile platinum-catalyzed hydrosilylation reaction between siloxane oligomers (linear spacers and netlike point molecules) and liquid-crystalline binary mixtures, composed of defined proportions of divinylic monomeric mesogens. First, the two sets of alternated, linear copolymers with disiloxane or trisiloxane chain extender, respectively, were investigated. They either exhibit both smectic C (SmC) and nematic (N) phases or a single SmC phase, the nature of which being dictated by the length of the inserted siloxane moieties, and the temperatures ranges regulated by the composition of the mesogenic mixture (mesogens ratio). As anticipated, the thermal behavior of the corresponding co-elas...

International audience; A series of nanometric isoreticular and/or functionalized analogues of the mesoporous environmentally-friendly iron( III ) polycarboxylates MIL-100/101 have been successfully synthesized. Their exceptional pore size, of up to 68 Å, together with their relatively good stability in solvents, makes them promising candidates for heterogeneous catalysis or inclusion of large molecules, among others.

This work describes an easy two-step approach for metal nitride/carbide nanocomposite ceramic nanofibers via heat treatment of electrospun precursor fibers. Possibilities to tune their composition, carbon scaffold organization and texture depend on the calcination temperature, and yield two different types of fiber structures. Fiber mats with various morphologies were obtained from polyacrylonitrile–chromium chloride precursor electrospun fibers, while well defined rod-like fiber non-woven mats were obtained when a methylated polyurea was used as an additive to the previous system. It was observed that the use of a two component organic system, involving a fiber stabilizing polymeric template (PAN) and a specific nitrogen/carbon donor (PUF), enables to maintain the morphology of the initial fibers during heat treatment and prevents the system from forming sintered membranes at high humidity conditions. The chromium content found for PAN-free and PAN-containing was 9 and 12 wt%, respectively. Moreover, thermal treatment at temperatures higher than 1000 °C led to graphitization of the carbon subphase of both series. Nitrogen sorption studies revealed that the graphitization process increases the specific surface area of the fibers, which possess a pore system with a wide diameter distribution and inkbottle-shaped pores. Conductivity studies revealed that the fiber systems are suitable for electrochemical applications.

A hybrid polymeric network has been achieved by using pre-functionalized 3.3 nm diameter iron oxide nanoparticles (NPs) as cross-linkers to reticulate mesogenic linear oligomers. A room-temperature smectic mesophase is induced in the network embedding NPs, and the magnetic properties remain almost unchanged, despite substantial changes of the environment around the ferrite cores.