scholarly journals Lanthanide-Based Metal–Organic Frameworks Solidified by Gelatin-Methacryloyl Hydrogels For Improving the Accuracy of Localization and Excision of Small Pulmonary Nodules

2021 ◽  
Author(s):  
Haoran Ji ◽  
Xiaofeng Wang ◽  
Pei Wang ◽  
Yan Gong ◽  
Yun Wang ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Fluorescence Emission ◽  
Pulmonary Nodules ◽  
Quantum Yields ◽  
X Rays ◽  
Important Concern ◽  
Metal Organic ◽  
Limited Application ◽  
Small Pulmonary Nodules ◽  
University Of Oslo

Abstract The localization of invisible and impalpable small pulmonary nodules has become an important concern during surgery, since current widely used techniques for localization, such as hookwires, microcoils, and indocyanine green (ICG), have a number of limitations. For example, hookwires and microcoils may cause complications because of their invasive features, while ICG undergoes rapid diffusion after injection and has limited application in the localization of deep-seated lesions. In contrast, lanthanide-based metal–organic frameworks (MOFs) have been proven as potential fluorescent agents because of their prominent luminescent characteristics, including large Stokes shifts, high quantum yields, long decay lifetimes, and undisturbed emissive energies. In addition, lanthanides, such as Eu, can efficiently absorb X-rays for CT imaging. In this study, we synthesized Eu-UiO-67-bpy (UiO = University of Oslo, bpy = 2,2'-bipyridyl) as a fluorescent dye with a gelatin-methacryloyl (GelMA) hydrogel as a liquid carrier. The prepared complex exhibits constant fluorescence emission owing to the luminescent characteristics of Eu and the stable structure of UiO-67-bpy with restricted fluorescence diffusion attributed to the photocured GelMA. Furthermore, the hydrogel provides stiffness to make the injection site tactile and improve the accuracy of localization and excision. Finally, our complex enables fluorescence-CT dual-modal imaging of the localization site.

scholarly journals Compressibility Studies of Zirconium Based Metal-Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan
Keyword(s):  
High Pressure ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
External Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pressure Medium ◽  
Metal Organic ◽  
University Of Oslo

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.

X-ray radiation-induced amorphization of metal–organic frameworks

2019 ◽  
Vol 21 (23) ◽  
pp. 12389-12395 ◽  
Author(s):  
Remo N. Widmer ◽  
Giulio I. Lampronti ◽  
Nicola Casati ◽  
Stefan Farsang ◽  
Thomas D. Bennett ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Metal Organic Frameworks ◽  
X Rays ◽  
X Ray ◽  
P Accumulation ◽  
Metal Organic ◽  
Radiation Induced ◽  
Crystalline Metal

Accumulation of radiation damage from synchrotron X-rays leads to complete amorphization of the initially crystalline metal–organic frameworks ZIF-4, ZIF-62, and ZIF-zni. The mechanism of this transformation is studied as a function of time and temperature and is shown to be non-isokinetic.

Bright blue emissions with temperature-dependent quantum yields from microporous metal–organic frameworks

2012 ◽  
Vol 48 (4) ◽  
pp. 531-533 ◽  
Author(s):  
Qilong Zhu ◽  
Chaojun Shen ◽  
Chunhong Tan ◽  
Tianlu Sheng ◽  
Shengmin Hu ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Quantum Yields ◽  
Temperature Dependent ◽  
Metal Organic ◽  
Bright Blue

scholarly journals Cinnamal Sensing and Luminescence Color Tuning in a Series of Rare-Earth Metal−Organic Frameworks with Trans-1,4-cyclohexanedicarboxylate

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5145
Author(s):  
Pavel A. Demakov ◽  
Alena A. Vasileva ◽  
Sergey S. Volynkin ◽  
Alexey A. Ryadun ◽  
Denis G. Samsonenko ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Earth Metal ◽  
Quantum Yields ◽  
Accessible Volume ◽  
Emission Color ◽  
Metal Organic ◽  
Cyclohexanedicarboxylic Acid ◽  
Bright Luminescence ◽  
Luminescence Color ◽  
Tunable Emission

Three isostructural metal–organic frameworks ([Ln2(phen)2(NO3)2(chdc)2]·2DMF (Ln3+ = Y3+ for 1, Eu3+ for 2 or Tb3+ for 3; phen = 1,10-phenanthroline; H2chdc = trans-1,4-cyclohexanedicarboxylic acid) were synthesized and characterized. The compounds are based on a binuclear block {M2(phen)2(NO3)2(OOCR)4} assembled into a two-dime nsional square-grid network containing tetragonal channels with 26% total solvent-accessible volume. Yttrium (1)-, europium (2)- and terbium (3)-based structures emit in the blue, red and green regions, respectively, representing the basic colors of the standard RGB matrix. A doping of Eu3+ and/or Tb3+ centers into the Y3+-based phase led to mixed-metal compositions with tunable emission color and high quantum yields (QY) up to 84%. The bright luminescence of a suspension of microcrystalline 3 in DMF (QY = 78%) is effectively quenched by diluted cinnamaldehyde (cinnamal) solutions at millimolar concentrations, suggesting a convenient and analytically viable sensing method for this important chemical.

scholarly journals Metal Organic Frameworks as Drug Targeting Delivery Vehicles in the Treatment of Cancer

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 232 ◽  
Author(s):  
Mengru Cai ◽  
Gongsen Chen ◽  
Liuying Qin ◽  
Changhai Qu ◽  
Xiaoxv Dong ◽  
...  
Keyword(s):  
Drug Targeting ◽  
Drug Loading ◽  
Metal Organic Frameworks ◽  
Zeolitic Imidazolate Frameworks ◽  
Passive Targeting ◽  
Normal Tissues ◽  
Excellent Research ◽  
Targeting Delivery ◽  
Metal Organic ◽  
University Of Oslo

In recent years, metal organic frameworks (MOFs) have been widely developed as vehicles for the effective delivery of drugs to tumor tissues. Due to the high loading capacity and excellent biocompatibility of MOFs, they provide an unprecedented opportunity for the treatment of cancer. However, drugs which are commonly used to treat cancer often cause side effects in normal tissue accumulation. Therefore, the strategy of drug targeting delivery based on MOFs has excellent research significance. Here, we introduce several intelligent targeted drug delivery systems based on MOFs and their characteristics as drug-loading systems, and the challenges of MOFs are discussed. This article covers the following types of MOFs: Isoreticular Metal Organic Frameworks (IRMOFs), Materials of Institute Lavoisier (MILs), Zeolitic Imidazolate Frameworks (ZIFs), University of Oslo (UiOs), and MOFs-based core-shell structures. Generally, MOFs can be reasonably controlled at the nanometer size to effectively achieve passive targeting. In addition, different ligands can be modified on MOFs for active or physicochemical targeting. On the one hand, the targeting strategy can improve the concentration of the drugs at the tumor site to improve the efficacy, on the other hand, it can avoid the release of the drugs in normal tissues to improve safety. Despite the challenges of clinical application of MOFs, MOFs have a number of advantages as a kind of smart delivery vehicle, which offer possibilities for clinical applications.

Tunable Solid-State Multicolor Emission in Substitutional Solid Solutions of Metal-Organic Frameworks

2019 ◽  
Author(s):  
Wesley Newsome ◽  
Suliman Ayad ◽  
Jesus Cordova ◽  
Eric Reinheimer ◽  
Andres Campiglia ◽  
...  
Keyword(s):  
Solid State ◽  
Solid Solutions ◽  
Hydrolytic Stability ◽  
Metal Organic Frameworks ◽  
Substitutional Solid Solution ◽  
Quantum Yields ◽  
Ambient Conditions ◽  
Excited State Proton Transfer ◽  
Substitutional Solid Solutions ◽  
Metal Organic

Realization of organic-based substitutional solid solutions will facilitate the preparation of solid-state materials with properties that arise from phenomena only displayed by molecules in solution. We demonstrate that multivariate metal-organic frameworks, MOFs, exhibit organic-based substitutional solid solution behavior by tuning their fluorescence, dictated exclusively by predetermined ratios of multivariate organic links. By combining non-fluorescent links with dilute mixtures of red, green, and blue fluorescent links we prepared zirconia-type MOFs that exhibit features of solution-like fluorescence. Our study found that MOFs with fluorophore link concentration of around 1 %mol exhibit fluorescence with decreased inner filtering demonstrated by changes in spectra profiles, quantum yields, and lifetime dynamics expected for excited state proton transfer emitters. Our findings enabled us to prepare organic-based substitutional solid solutions with tunable chromaticity. These materials emit multicolor and white light with high quantum yields, long shelf life, and superb hydrolytic stability at ambient conditions.

scholarly journals Crystallographic studies of gas sorption in metal–organic frameworks

2014 ◽  
Vol 70 (3) ◽  
pp. 404-422 ◽  
Author(s):  
Elliot J. Carrington ◽  
Iñigo J. Vitórica-Yrezábal ◽  
Lee Brammer
Keyword(s):  
Energy Transport ◽  
Modular Design ◽  
Metal Organic Frameworks ◽  
X Rays ◽  
Gas Sorption ◽  
Sorption Behaviour ◽  
Crystalline Materials ◽  
Metal Organic ◽  
Gas Molecules

Metal–organic frameworks (MOFs) are a class of porous crystalline materials of modular design. One of the primary applications of these materials is in the adsorption and separation of gases, with potential benefits to the energy, transport and medical sectors.In situcrystallography of MOFs under gas atmospheres has enabled the behaviour of the frameworks under gas loading to be investigated and has established the precise location of adsorbed gas molecules in a significant number of MOFs. This article reviews progress in such crystallographic studies, which has taken place over the past decade, but has its origins in earlier studies of zeolites, clathratesetc. The review considers studies by single-crystal or powder diffraction using either X-rays or neutrons. Features of MOFs that strongly affect gas sorption behaviour are discussed in the context ofin situcrystallographic studies, specifically framework flexibility, and the presence of (organic) functional groups and unsaturated (open) metal sites within pores that can form specific interactions with gas molecules.

scholarly journals Synthesis, Structure and Fluorescence Properties of Two Metal-Organic Frameworks Based on a Benzimidazole-Derived Ligand

2018 ◽  
Vol 42 (8) ◽  
pp. 424-427 ◽  
Author(s):  
Junfeng Li ◽  
Xiudian Xu ◽  
Lei Zhou ◽  
Zeyu Zhou ◽  
Lizhuang Chen ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Porous Structure ◽  
Crystal Structures ◽  
Metal Organic Frameworks ◽  
Fluorescence Emission ◽  
Fluorescence Properties ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Metal Organic ◽  
3D Framework

The luminescent complexes [Cd(BIMP)2(NDC)2]n and [Zn(BIMP)2(NDC)]n (where (3-BIMP) = 3-(1H-benzoimidazol-2-yl)pyridin-2(1H)-one and NDC = 2,6-naphthalenedicarboxylic acid) have been synthesised under hydrothermal conditions and their crystal structures determined. [Cd(BIMP)2(NDC)2]n exhibited a 1D → 2D → 3D framework structure and [Zn(BIMP)2(NDC)]n has a 3D porous structure. Under the same excitation energy (λex = 389 nm), [Zn(BIMP)2(NDC)]n showed a stronger fluorescence emission than the free 3-BIMP ligand, the NDC ligand and [Cd(BIMP)2(NDC)2]n.

scholarly journals Nanocomposites for X-Ray Photodynamic Therapy

2020 ◽  
Vol 21 (11) ◽  
pp. 4004 ◽  
Author(s):  
Zaira Gadzhimagomedova ◽  
Peter Zolotukhin ◽  
Oleg Kit ◽  
Daria Kirsanova ◽  
Alexander Soldatov
Keyword(s):  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Metal Organic Frameworks ◽  
Reactive Oxygen ◽  
Modern Medicine ◽  
Oxygen Species ◽  
X Rays ◽  
X Ray ◽  
Metal Organic ◽  
Cancer Tissues

Photodynamic therapy (PDT) has long been known as an effective method for treating surface cancer tissues. Although this technique is widely used in modern medicine, some novel approaches for deep lying tumors have to be developed. Recently, deeper penetration of X-rays into tissues has been implemented, which is now known as X-ray photodynamic therapy (XPDT). The two methods differ in the photon energy used, thus requiring the use of different types of scintillating nanoparticles. These nanoparticles are known to convert the incident energy into the activation energy of a photosensitizer, which leads to the generation of reactive oxygen species. Since not all photosensitizers are found to be suitable for the currently used scintillating nanoparticles, it is necessary to find the most effective biocompatible combination of these two agents. The most successful combinations of nanoparticles for XPDT are presented. Nanomaterials such as metal–organic frameworks having properties of photosensitizers and scintillation nanoparticles are reported to have been used as XPDT agents. The role of metal–organic frameworks for applying XPDT as well as the mechanism underlying the generation of reactive oxygen species are discussed.

The origin of the measured chemical shift of 129Xe in UiO-66 and UiO-67 revealed by DFT investigations

2017 ◽  
Vol 19 (15) ◽  
pp. 10020-10027 ◽  
Author(s):  
Kai Trepte ◽  
Jana Schaber ◽  
Sebastian Schwalbe ◽  
Franziska Drache ◽  
Irena Senkovska ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Chemical Shift ◽  
Density Functional ◽  
Metal Organic Frameworks ◽  
Functional Theory ◽  
Xenon Isotope ◽  
Metal Organic ◽  
University Of Oslo

The NMR chemical shift of the xenon isotope 129Xe inside the metal–organic frameworks (MOFs) UiO-66 and UiO-67 (UiO – University of Oslo) has been investigated both with density functional theory (DFT) and in situ high-pressure 129Xe NMR measurements.

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