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CRISPR-based biosensing technology has been emerging as a revolutionary diagnostic tool for many disease-related biomarkers. In particular, RspCas13d, a newly identified RNA-guided Cas13d ribonuclease derived from Ruminococcus sp., has shown great promise for accurate and sensitive detection of RNA due to its RNA sequence-specific recognition and robust collateral trans-cleavage activity. However, its diagnostic utility is limited to detecting nucleic-acid-related biomarkers. To address this limitation, herein we present a proof-of-concept demonstration of a target-responsive CRISPR-Cas13d sensing system for protein biomarkers. This system was rationally designed by integrating a dual-aptamer-based transcription amplification strategy with CRISPR-Cas13d (DATAS-Cas13d), in which the protein binding initiates in-vitro RNA transcription followed by the activation of RspCas13d. Using a short fluorescent ssRNA as the signal reporter and cardiac troponin I (cTnI) as the model analyte, the DATAS-Cas13d system showed a wide linear range, low detection limit, and high specificity for the detection of cTnI in buffer and human serum. Thanks to the facile integration of various bioreceptors into the DATAS-Cas13d system, the method could be adapted to detecting a broad range of clinically relevant protein biomarkers, and thus broaden the medical applications of Cas13d-based diagnostics., (© 2022 Wiley-VCH GmbH.)

A Zr-based metal-organic polyhedron (MOP) was self-assembled in a porous MOF host, DUT-68, successfully to synthesize MOP-1@DUT-68. The MOP guest (MOP-1) has a diameter of about 20 Å, larger than that of the square windows (pore sizes of ∼14 Å) of DUT-68 but smaller than that of the rhombicuboctahedral cage (27.7 Å), which means that the migration and leaching of MOP-1 could be effectively prohibited if MOP-1 is encapsulated in the MOF's cavities. The proton conductivity of MOP-1@DUT-68 is 1.14×10 -3  S cm -1 (at 80 °C under 98 % relative humidity), which is three orders of magnitude higher than that of DUT-68. Compared with MOP-1⊂DUT-68, which was synthesized by impregnation, MOP-1@DUT-68 is more prone to form faster proton-conduction pathways and thus provides higher proton conductivity., (© 2021 Wiley-VCH GmbH.)

An unprecedented reversible dynamic transformation is reported in a metal-organic framework involving bond formation, which is accompanied by two important structural changes; achiral to chiral and two- to three-dimensions. Using two bent organic ligands (diimpym=4,6-di(1H-imidazol-1-yl)pyrimidine; H 2 npta=5-nitroisophthalic acid) and Co II (NO 3 ) 2 ⋅6 H 2 O the coordination polymer Co(diimpym)(npta)⋅CH 3 OH, (1⋅CH 3 OH), was obtained solvothermally. Its structure consists of knitted pairs of square layers (4 4 -sql net) of five-coordinated Co and disordered methanol, and it crystallized in the achiral Pbca space group at room temperature. It undergoes a single crystal to single crystal (SC-SC) transformation to a 3D interpenetrated framework (α-polonium-type net, pcu) of six-coordinated Co and ordered methanol in the chiral P2 1 2 1 2 1 space group below 220 K. Most unusual is the dynamic temperature-dependent shortening of a Co⋅⋅⋅O connection from a non-bonded 2.640 Å (298 K) to a bonded 2.347 Å distance (100 K) transforming the square pyramidal cobalt polyhedron to a distorted octahedron. The desolvated crystals (1) obtained at 480 K retain the full crystallinity and crystallize in the achiral Pbca space group between 100 and 298 K but the dynamic shortening of the Co⋅⋅⋅O distance connecting the layers into the 3D pcu framework structure is observed. Following post-synthetic insertion of ethanol (1⋅CH 3 CH 2 OH) it does not exhibit the transformation and retains the knitted 2D achiral Pbca structure for all temperatures (100-298 K) and the ethanol is always disordered. The structural analyses thus conclude that the ordering of the methanol induces the chirality while the available space controls the dynamic motion of the knitted 2D networks into the 3D interpenetrated framework. Consequently, 1 selectively adsorbs CO 2 to N 2 and exhibits Type-III isotherms indicating dynamic motion of the 2D networks to accommodate the CO 2 at 273 and 298 K in contrast to the rigidity of the 3D framework at 77 K preventing N 2 from penetrating the solid. The magnetic properties are also reported., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Assembly of small clusters into rigid bodies with precise shape and symmetry has been witnessed by the significant advances in cluster-based metal-organic frameworks (MOFs), however, nanosized silver cluster based MOFs remain largely unexplored. Herein, two anion-templated silver clusters, CO3 @Ag20 and SO4 @Ag22 , were ingeniously incorporated into a 2D sql lattice (1, [CO3 @Ag20 (iPrS)10 (NO3 )8 (DMF)2 ]n ) and an unprecedented 3D two-fold interpenetrated dia network (2, [SO4 @Ag22 (iPrS)12 (NO3 )6 ⋅2 NO3 ]n ), respectively, under mild solvothermal conditions. Their atomically precise structures were confirmed by single-crystal X-ray diffraction analysis and further consolidated by IR spectroscopy, thermogravimetric analysis (TGA), and elemental analysis. Each drum-like CO3 @Ag20 cluster is extended by twelve NO3 (-) ions to form the 2D sql lattice of 1, whereas each ball-shaped SO4 @Ag22 cluster with a twisted truncated tetrahedral geometry is pillared by four [Ag6 (NO3 )3 ] triangular prisms to form the 3D interpenetrated dia network of 2. Notably, 2 is the first interpenetrated 3D MOF constructed from silver clusters. These results demonstrate the dual role of the anions, which not only internally act as anion templates to induce the formation of silver thiolate clusters but also externally extend the cluster units into the rigid networks. The photoluminescent and electrochemical properties of 2 are discussed in detail., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Previous studies from our laboratory have shown that some in vitro maintained Leishmania major-specific L3T4+ T cells were capable of exacerbating cutaneous leishmaniasis after adoptive transfer to normal syngeneic mice. Results presented in this report show that these cells released substantial amounts of interleukin 3 (IL 3) and granulocyte-macrophage colony-stimulating factors after specific stimulation in vitro. In order to assess the involvement of such lymphokines in the exacerbation of cutaneous leishmaniasis by these L3T4+ T cells, the effect of the administration of important doses of IL 3 on the course of infection with L. major was investigated. The treatment of genetically susceptible BALB/c mice with IL 3 resulted in an enhancement of the size of lesions and favored the multiplication of parasites at anatomical sites distant from the primary lesion. Although IL 3 did not modify the development of lesions in genetically resistant CBA mice, this lymphokine promoted the growth of Leishmania in lymph node draining the lesion. Finally, the addition of IL 3 to macrophages parasitized in vitro enhanced the survival of intracellular Leishmania major.