Controllable surfactant-directed zeolitic-imidazolate-8 growth on swollen 2D zeolites

The authors would like to thank the European Research Council for funding opportunities under Advanced Grant No. 787073. The EPSRC Light Element Analysis Facility under Grant No. EP/T019298/1 and the EPSRC Strategic Equipment Resource under Grant No. EP/R023751/1 are gratefully acknowledged.To meet society’s need for more and more specialized materials, this work focuses on the preparation of porous metal–organic framework (MOF)–zeolite hybrid materials based on two 2D zeolites, namely, IPC-1P (Institute of Physical Chemistry - 1 Precursor) and the metal–organic framework ZIF-8 (Zeolitic Imidazolate Framework-8). Using the previously well-established assembly–disassembly–organization–reassembly method, the zeolite was (i) synthesized, (ii) hydrolyzed to a layered zeolite, (iii) the interlayer distance was increased using the swelling agent cetyltrimethylammonium chloride, and (iv) nanocrystals of ZIF-8 were grown stepwise on the zeolite surface but predominantly at the edges of the crystallites where the openings to the interlayer region are located. This selective MOF growth and attachment was facilitated by a combination of intercalation of the metal ions and the swelling agent between the zeolite layers. The influence of the solvent and the number of additional steps on the ZIF-8 growth on the zeolite was systematically investigated, and the synthesis protocol was successfully adapted to a further two-dimensional silicate RUB-18 (Ruhr-Universität Bochum - 18). This paves the way toward the controlled preparation of more MOF–zeolite hybrid materials, which might provide interesting properties for future applications.Publisher PDFPeer reviewe

Biomedical metal–organic framework materials : perspectives and challenges

The authors gratefully acknowledge financial support from the German Research Foundation (DFG: LA2937/4-1; SH1223/1-1; SFB 1066; GRK/RTG 2735 (project number 331065168)), the German Federal Ministry of Research and Education (BMBF: Gezielter Wirkstofftransport, PP-TNBC, Project No. 16GW0319K) and the European Research Council (ERC: Meta-Targeting (864121)). The financial support from Welch Foundation (AT-1989-20220331) and from the Human Frontier Science Program (HFSP, within the project RGP0047/2022) are also acknowledged. The authors thank the European Union (European Cooperation in Science and Technology) for the COST Action EU4MOFs (CA22147). Figures were created using BioRender.com.Metal–organic framework (MOF) materials are gaining significant interest in biomedical research, owing to their high porosity, crystallinity, and structural and compositional diversity. Their versatile hybrid organic/inorganic chemistry endows MOFs with the capacity to retain organic (drug) molecules, metals, and gases, to effectively channel electrons and photons, to survive harsh physiological conditions such as low pH, and even to protect sensitive biomolecules. Extensive preclinical research has been carried out with MOFs to treat several pathologies and, recently, their integration with other biomedical materials such as stents and implants has demonstrated promising performance in regenerative medicine. However, there remains a significant gap between MOF preclinical research and translation into clinically and societally relevant medicinal products. Here, the intrinsic features of MOFs are outlined and their suitability to specific biomedical applications such as detoxification, drug and gas delivery, or as (combination) therapy platforms is discussed. Furthermore, relevant examples of how MOFs have been engineered and evaluated in different medical indications, including cancer, microbial, and inflammatory diseases is described. Finally, the challenges facing their translation into the clinic are critically examined, with the goal of establishing promising research directions and more realistic approaches that can bridge the translational gap of MOFs and MOF‐containing (nano)materials.Publisher PDFPeer reviewe

Mixed metal-organic framework mixed-matrix membranes : insights into simultaneous moisture-triggered and catalytic delivery of nitric oxide using cryo-scanning electron microscopy

Funding: This work was supported by the European Research Council grant ADOR (Advanced Grant 787073). The authors acknowledge the EPSRC Light Element Analysis Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1).The fundamental chemical and structural diversity of metal–organic frameworks (MOFs) is vast, but there is a lack of industrial adoption of these extremely versatile compounds. To bridge the gap between basic research and industry, MOF powders must be formulated into more application-relevant shapes and/or composites. Successful incorporation of varying ratios of two different MOFs, CPO-27-Ni and CuBTTri, in a thin polymer film represents an important step toward the development of mixed MOF mixed-matrix membranes. To gain insight into the distribution of the two different MOFs in the polymer, we report their investigation by Cryo-scanning electron microscopy (Cryo-SEM) tomography, which minimizes surface charging and electron beam-induced damage. Because the MOFs are based on two different metal ions, Ni and Cu, the elemental maps of the MOF composite cross sections clearly identify the size and location of each MOF in the reconstructed 3D model. The tomography run was about six times faster than conventional focused ion beam (FIB)-SEM and the first insights to image segmentation combined with machine learning could be achieved. To verify that the MOF composites combined the benefits of rapid moisture-triggered release of nitric oxide (NO) from CPO-27-Ni with the continuous catalytic generation of NO from CuBTTri, we characterized their ability to deliver NO individually and simultaneously. These MOF composites show great promise to achieve optimal dual NO delivery in real-world medical applications.Publisher PDFPeer reviewe

In situ single-crystal X-ray diffraction studies of physisorption and chemisorption of SO2 within a metal-organic framework and its competitive adsorption with water

Funding: The authors are also grateful for financial assistancefrom the ERC under advanced grant 787073, the EPSRC for a studentship (EP/N509759/1) and support via the Collaborative Computational Projecton NMR Crystallography CCP-NC (EP/T02662/1), and the CRITICAT Centre for Doctoral Training (EP/L016419/1).Living on an increasingly polluted planet, the removal of toxic pollutants such as sulfur dioxide (SO2) from the troposphere and power station flue gas is becoming more and more important. The CPO-27/MOF-74 family of metal–organic frameworks (MOFs) with their high densities of open metal sites is well suited for the selective adsorption of gases that, like SO2, bind well to metals and have been extensively researched both practically and through computer simulations. However, until now, focus has centered upon the binding of SO2 to the open metal sites in this MOF (called chemisorption, where the adsorbent–adsorbate interaction is through a chemical bond). The possibility of physisorption (where the adsorbent–adsorbate interaction is only through weak intermolecular forces) has not been identified experimentally. This work presents an in situ single-crystal X-ray diffraction (scXRD) study that identifies discrete adsorption sites within Ni-MOF-74/Ni-CPO-27, where SO2 is both chemisorbed and physisorbed while also probing competitive adsorption of SO2 of these sites when water is present. Further features of this site have been confirmed by variable SO2 pressure scXRD studies, DFT calculations, and IR studies.Publisher PDFPeer reviewe

Long-term whole blood DNA preservation by cost-efficient cryosilicification

This work was supported by the National Natural Science Foundation of China (21972047 to W.Z., 52003086 to Q.L.), Guangdong Provincial Pearl River Talents Program (2019QN01Y314 to Q.L.), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2019ZT08Y318 to W.Z.), Natural Science Foundation of Guangdong Province, China (2021A1515010724 to Q.L.), China Postdoctoral Science Foundation (2020M672625, 2021T140213 to Q.L.), Science and Technology Project of Guangzhou, China (202102020352 to W.Z., 202102020259 to Q.L.), the Fundamental Research Funds for the Central Universities of China. The authors thank the support from the Guangzhou Women and Children’s Medical Center and Laboratory Animal Research Center of the South China University of Technology. S.W. acknowledges funding from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs.Deoxyribonucleic acid (DNA) is the blueprint of life, and cost-effective methods for its long-term storage could have many potential benefits to society. Here we present the method of in situ cryosilicification of whole blood cells, which allows long-term preservation of DNA. Importantly, our straightforward approach is inexpensive, reliable, and yields cryosilicified samples that fulfill the essential criteria for safe, long-term DNA preservation, namely robustness against external stressors, such as radical oxygen species or ultraviolet radiation, and long-term stability in humid conditions at elevated temperatures. Our approach could enable the room temperature storage of genomic information in book-size format for more than one thousand years (thermally equivalent), costing only 0.5 $/person. Additionally, our demonstration of 3D-printed DNA banking artefacts, could potentially allow 'artificial fossilization'.Publisher PDFPeer reviewe

Surface functionalized metal-organic frameworks for binding coronavirus proteins

This work was supported by University of St Andrews Restarting Research Funding Scheme (SARRF), funded through the SFC grant reference SFC/AN/08/020 (XRR064) and European Research Council grant ADOR (Advanced Grant 787073). The authors acknowledge the EPSRC Light Element Analysis Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1).Since the outbreak of SARS-CoV-2, a multitude of strategies have been explored for the means of protection and shielding against virus particles: filtration equipment (PPE) has been widely used in daily life. In this work, we explore another approach in the form of deactivating coronavirus particles through selective binding onto the surface of metal–organic frameworks (MOFs) to further the fight against the transmission of respiratory viruses. MOFs are attractive materials in this regard, as their rich pore and surface chemistry can easily be modified on demand. The surfaces of three MOFs, UiO-66(Zr), UiO-66-NH2(Zr), and UiO-66-NO2(Zr), have been functionalized with repurposed antiviral agents, namely, folic acid, nystatin, and tenofovir, to enable specific interactions with the external spike protein of the SARS virus. Protein binding studies revealed that this surface modification significantly improved the binding affinity toward glycosylated and non-glycosylated proteins for all three MOFs. Additionally, the pores for the surface-functionalized MOFs can adsorb water, making them suitable for locally dehydrating microbial aerosols. Our findings highlight the immense potential of MOFs in deactivating respiratory coronaviruses to be better equipped to fight future pandemics.Publisher PDFPeer reviewe

Herstellung und Charakterisierung von Metall-organischen Gerüstverbindungen als Drug Delivery System für arsenhaltige Wirkstoffe

In jüngster Zeit wurde die Eignung hochtoxischer arsenhaltiger Verbindungen, wie Arsentrioxid (ATO), als äußerst nützliches und vielversprechendes Medikament in der Krebsforschung wiederentdeckt. Ihre hohe Toxizität erschwert allerdings deren Einsatz in höheren therapeutischen Dosen und somit die Behandlung von soliden Tumorentitäten. Daher wird in dieser Arbeit ein neuartiger Ansatz vorgestellt diese Problematik anzugehen. Es wurden erstmals Metall-organische Gerüstverbindungen (zu engl.: Metal-Organic Frameworks = MOFs) als Drug Delivery System für arsenhaltige Wirkstoffe eingeführt. Auf der Basis präzise ausgearbeiteter Beladungsstrategien ist es dabei erfolgreich gelungen hohe Mengen an arsenhaltigen Wirkstoffen postsynthetisch über koordinative Bindungen direkt in das Netzwerk von drei verschiedenen MOFs, namens MFU-4l, Zn-MOF-74 und ZIF-8, zu integrieren. Diese Modellbeispiele für MOF-basierte Trägermaterialien übertreffen die bisher in der Literatur bekannten ATO-Trägermaterialien im Hinblick auf die essenziellen Kriterien deutlich: Neben einer hohen Wirkstoff-Beladungskapazität ermöglichen diese nämlich auch eine günstige pH-gesteuerte Freisetzung. Zudem konnten vielversprechende Resultate in ersten in vitro Zytotoxizitätsstudien erzielt werden. Desweiteren wurde das erste Modellbeispiel für ein MOF-basiertes Theragnostikum, namens Fe3O4-ZIF-8, für arsenhaltige Wirkstoffe entwickelt und charakterisiert. Dieses hat sich sowohl als ein geeignetes pH-sensitives Drug Delivery System und gleichzeitig als effektives Magnet-resonanztomographie-Kontrastmittel erwiesen. Die erlangten Erkenntnisse dieser Arbeit erweitern das bestehende Wissen zur Behandlung solider Tumorentitäten und stellen folglich einen wichtigen Fortschritt bei der Entwicklung alternativer Therapien in der Krebsforschung dar