A Highly Porous Metal-Organic Framework System to Deliver Payloads for Gene Knockdown

© 2019 Elsevier Inc. Gene knockdown is an advantageous therapeutic strategy to lower dangerous genetic over-expression. However, the molecules responsible for initiating this process are unstable. Porous nanoparticles called metal-organic frameworks can encapsulate, protect, and deliver these compounds efficaciously without the need for chemical modifications—commonly done to enhance stability. By applying this platform technology, this work demonstrates the successful reduction in expression of a gene by avoiding retention and subsequent degradation in cellular compartments.This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (NanoMOFdeli), ERC-2016-COG 726380, and (SUPUVIR) no. 722380. M.H.T. thanks the Gates Cambridge Trust for funding, S. Haddad for helpful discussions, and A. Li for assistance with data visualization. D.F.-J. thanks the Royal Society for funding through a University Research Fellowship. S.B.d.Q.F., F.M.R., and D.I.J. were funded by Cancer Research UK Senior Group Leader Grant CRUK/A15678. O.K.F. gratefully acknowledges DTRA for financial support (grant HDTRA-1-14-1-0014). C.F.K. acknowledges funding from the UK Engineering and Physical Sciences Research Council (grants EP/L015889/1 and EP/H018301/1), the Wellcome Trust (grants 3-3249/Z/16/Z and 089703/Z/09/Z) and the UK Medical Research Council (grants MR/K015850/1 and MR/K02292X/1), and Infinitus (China) Ltd. Computational work was supported by the Cambridge High Performance Computing Cluster, Darwin

Tuning porosity in macroscopic monolithic metal-organic frameworks for exceptional natural gas storage.

Widespread access to greener energy is required in order to mitigate the effects of climate change. A significant barrier to cleaner natural gas usage lies in the safety/efficiency limitations of storage technology. Despite highly porous metal-organic frameworks (MOFs) demonstrating record-breaking gas-storage capacities, their conventionally powdered morphology renders them non-viable. Traditional powder shaping utilising high pressure or chemical binders collapses porosity or creates low-density structures with reduced volumetric adsorption capacity. Here, we report the engineering of one of the most stable MOFs, Zr-UiO-66, without applying pressure or binders. The process yields centimetre-sized monoliths, displaying high microporosity and bulk density. We report the inclusion of variable, narrow mesopore volumes to the monoliths' macrostructure and use this to optimise the pore-size distribution for gas uptake. The optimised mixed meso/microporous monoliths demonstrate Type II adsorption isotherms to achieve benchmark volumetric working capacities for methane and carbon dioxide. This represents a critical advance in the design of air-stable, conformed MOFs for commercial gas storage

Nitro-functionalized Bis(pyrazolate) Metal–Organic Frameworks as Carbon Dioxide Capture Materials under Ambient Conditions

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The metal–organic frameworks (MOFs) M(BPZNO2) (M=Co, Cu, Zn; H2BPZNO2=3-nitro-4,4′-bipyrazole) were prepared through solvothermal routes and were fully investigated in the solid state. They showed good thermal stability both under a N2 atmosphere and in air, with decomposition temperatures peaking up to 663 K for Zn(BPZNO2). Their crystal structure is characterized by 3D networks with square (M=Co, Zn) or rhombic (M=Cu) channels decorated by polar NO2 groups. As revealed by N2 adsorption at 77 K, they are micro-mesoporous materials with BET specific surface areas ranging from 400 to 900 m2 g−1. Remarkably, under the mild conditions of 298 K and 1.2 bar, Zn(BPZNO2) adsorbs 21.8 wt % CO2 (4.95 mmol g−1). It shows a Henry CO2/N2 selectivity of 15 and an ideal adsorbed solution theory (IAST) selectivity of 12 at p=1 bar. As a CO2 adsorbent, this compound is the best-performing MOF to date among those bearing a nitro group as a unique chemical tag. High-resolution powder X-ray diffraction at 298 K and different CO2 loadings revealed, for the first time in a NO2-functionalized MOF, the insurgence of primary host–guest interactions involving the C(3)–NO2 moiety of the framework and the oxygen atoms of carbon dioxide, as confirmed by Grand Canonical Monte Carlo simulations. This interaction mode is markedly different from that observed in NH2-functionalized MOFs, for which the carbon atom of CO2 is involved

Structure-Mechanical Stability Relations of Metal-Organic Frameworks via Machine Learning

Development of new materials via experiments alone is costly and can take years, if not decades, to complete. Advancements in the predictive power of computer simulations have enhanced our ability to design and develop materials in a fraction of the time required for experiments. Here, we demonstrate how the power of machine learning, trained by a combination of multi-level simulations, can predict the performance of metal-organic frameworks (MOFs), one of the most exciting advances of porous materials science. The machine-learning algorithm introduced here predicts the mechanical properties of existing and future MOFs in the order of seconds, allowing the design of robust structures. The principles of our computational approach can be translated to other problems so that MOF researchers can discover new materials for application in, e.g., catalysis, energy storage, and chemicals separation. We anticipate that our work will guide future efforts to make stable MOFs suitable for industry

Nitro-functionalized Bis(pyrazolate) Metal–Organic Frameworks as Carbon Dioxide Capture Materials under Ambient Conditions

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The metal–organic frameworks (MOFs) M(BPZNO2) (M=Co, Cu, Zn; H2BPZNO2=3-nitro-4,4′-bipyrazole) were prepared through solvothermal routes and were fully investigated in the solid state. They showed good thermal stability both under a N2 atmosphere and in air, with decomposition temperatures peaking up to 663 K for Zn(BPZNO2). Their crystal structure is characterized by 3D networks with square (M=Co, Zn) or rhombic (M=Cu) channels decorated by polar NO2 groups. As revealed by N2 adsorption at 77 K, they are micro-mesoporous materials with BET specific surface areas ranging from 400 to 900 m2 g−1. Remarkably, under the mild conditions of 298 K and 1.2 bar, Zn(BPZNO2) adsorbs 21.8 wt % CO2 (4.95 mmol g−1). It shows a Henry CO2/N2 selectivity of 15 and an ideal adsorbed solution theory (IAST) selectivity of 12 at p=1 bar. As a CO2 adsorbent, this compound is the best-performing MOF to date among those bearing a nitro group as a unique chemical tag. High-resolution powder X-ray diffraction at 298 K and different CO2 loadings revealed, for the first time in a NO2-functionalized MOF, the insurgence of primary host–guest interactions involving the C(3)–NO2 moiety of the framework and the oxygen atoms of carbon dioxide, as confirmed by Grand Canonical Monte Carlo simulations. This interaction mode is markedly different from that observed in NH2-functionalized MOFs, for which the carbon atom of CO2 is involved