Toward Engineering Chiral Rodlike Metal-Organic Frameworks with Rare Topologies

The establishment of novel design strategies to target chiral rodlike MOFs, elusively faced until now, is one of the most straightforward manners to widen the scope of MOFs. Here we describe our last advances on the application of the metalloligand design strategy toward the development of efficient routes to obtain chiral rodlike MOFs. To this end, we have used as precursor an enantiopure homochiral hexanuclear wheel (1), derived from the amino acid d-valine, which, after a supramolecular reorganization into a one-dimensional homochiral chain-with the same configuration as 1-led to the formation of a homochiral rodlike MOF (2) exhibiting rare etd topology

Phase transfer of rhodium(II)-based metal-organic polyhedra bearing coordinatively bound cargo enables molecular separation

The transfer of nanoparticles between immiscible phases can be driven by externally triggered changes in their surface composition. Interestingly, phase transfers can enhance the processing of nanoparticles and enable their use as vehicles for transporting molecular cargo. Herein we report extension of such phase transfers to encompass porous metal-organic polyhedra (MOPs). We report that a hydroxyl-functionalized, cuboctahedral Rh(II)-based MOP can be transferred between immiscible phases by pH changes or by cation-exchange reactions. We demonstrate use of this MOP to transport coordinatively bound cargo between immiscible layers, including into solvents in which the cargo is insoluble. As proof-of-concept that our phase-transfer approach could be used in chemical separation, we employed Rh(II)-based MOPs to separate a challenging mixture of structurally similar cyclic aliphatic (tetrahydrothiophene) and aromatic (thiophene) compounds. We anticipate that transport of coordinatively bound molecules will open new avenues for molecular separation based on the relative coordination affinity that the molecules have for the Rh(II) sites of MOP.Thais Grancha, Arnau Carné-Sánchez, Laura Hernández-López, Jorge Albalad, Inhar Imaz, Judith Juanhuix, and Daniel Maspoc

A physiological function of inflammation-associated SerpinB2 is regulation of adaptive immunity

SerpinB2 (plasminogen activator inhibitor-2) is widely described as an inhibitor of urokinase plasminogen activator; however, SerpinB2(-/-) mice show no detectable increase in urokinase plasminogen activator activity. In this study, we describe an unexpected immune phenotype in SerpinB2(-/-) mice. After immunization with OVA in CIA, SerpinB2(-/-) mice made approximate to 6-fold more IgG2c and generated approximate to 2.5-fold more OVA-specific IFN-gamma-secreting T cells than SerpinB2(+/+) littermate controls. In SerpinB2(+/+) mice, high inducible SerpinB2 expression was seen at the injection site and in macrophages low levels in draining lymph nodes and conventional dendritic cells, and no expression was seen in plasmacytoid dendritic, B, T, or NK cells. SerpinB2(-/-) macrophages promoted greater IFN-gamma secretion from wild-type T cells in vivo and in vitro and, when stimulated with anti-CD40/IFN-gamma or cultured with wild-type T cells in vitro, secreted more Th1-promoting cytokines than macrophages from littermate controls. Draining lymph node SerpinB2(-/-) myeloid APCs similarly secreted more Th1-promoting cytokines when cocultured with wild-type T cells. Regulation of Th1 responses thus appears to be a physiological function of inflammation-associated SerpinB2; an observation that may shed light on human inflammatory diseases like pre-eclampsia, lupus, asthma, scleroderma, and periodontitis, which are associated with SerpinB2 polymorphisms or dysregulated SerpinB2 expression. The Journal of Immunology, 2010, 184: 2663-2670