Two porphyrinic metal-organic frameworks (PCN-222 and PCN-224) were prepared and their potential as molybdenum adsorbents for the ⁹⁹Mo/^99mTc generator was explored. The molybdenum adsorption properties of the two adsorbents, including adsorption kinetics and equilibrium isotherms, were evaluated at different molybdenum concentrations and pH. The maximum adsorption capacity of PCN-222 and PCN-224 was evaluated to be 525 mg g⁻¹ and 455 mg g⁻¹, respectively. The possible adsorption mechanism was investigated by X-ray Photoelectron Spectra and Fourier-Transform Infrared Spectroscopy. The results demonstrated that molybdenum species were adsorbed on the two MOFs through electrostatic attraction and hydrogen bonds. In the case of PCN-222, the Mo-O-Zr coordination interaction also played an important role. Additionally, the elution performance of two ⁹⁹Mo/^99mTc generators developed by using PCN-222 and PCN-224 as adsorbents was measured to assess possible clinical applications. The PCN-222-based ⁹⁹Mo/^99mTc generator exhibited better elution performance and showed that around 56% of ^99mTc could be obtained without zirconium breakthrough when relatively high pH solutions were used (pH = 9.6).

The cerium-based metal–organic framework UiO-66 (Ce) was examined as a potential adsorbent for the ⁹⁹Mo/^99mTc generator. The results showed that the adsorbent had an outstanding adsorption performance, reaching up to 475 mg/g adsorption capacity at pH 3. An adsorption mechanism was proposed, where the adsorption was governed by hydrogen bonds, Ce-O-Mo coordination, π-anions and electrostatic interaction. Additionally, the adsorbent exhibited excellent radiation stability and good adsorption performance when radioactive ⁹⁹Mo was applied. A ⁹⁹Mo/^99mTc generator was fabricated with UiO-66 (Ce) as adsorbent and its performance was evaluated over two weeks. The elution results showed that 92 ± 3% of ^99mTc elution efficiency could be obtained with negligible cerium breakthrough, showing the great potential of UiO-66 (Ce) as adsorbent for ⁹⁹Mo/^99mTc generators.

Four different MOFs were exposed to γrays by a cobalt-60 source reaching a maximum dose of 5 MGy. The results showed that the MIL-100 (Cr) and MIL-100 (Fe) did not exhibit obvious structural damage, suggesting their excellent radiation stability. MIL-101 (Cr) showed good radiation stability up to 4 MGy, but its structure started degrading with increasing radiation dose. Furthermore, the results showed that the structure of AlFu MOFs started to decompose at a gamma dose of 1 MGy, exhibiting a much lower tolerance to γradiation. At this radiation energy, the dominant interaction of the gamma-ray with MOFs is the Compton effect and the radiation stability of MOFs can be improved by prolific aromatic linkers, high linker connectivity, and good crystallinity. The results of this study indicate that MIL-100 and MIL-101 MOFs have a good potential to be employed in nuclear applications, where relatively high radiation doses play a role, for example, nuclear waste treatment and radionuclides production.

The potential of the metal–organic framework UiO-66 and its functionalized derivatives for their utilization in the ⁹⁹Mo/^99mTc generator was assessed. Molybdenum adsorption experiments, structure characterization, molecular simulations and column experiments with molybdenum-99 were carried out. The results showed that the maximum molybdenum adsorption capacity achieved for UiO-66 was 335 mg g⁻¹. Adsorption on the surface of the UiO-66 occurs via electrostatic interaction and DFT calculations verified the enhanced affinity between the adsorbents and the molybdenum ions by Zr-O-Mo coordination, anion-π as well as hydrogen bonds. In addition, the performance of a ⁹⁹Mo/^99mTc generator fabricated with Form-UiO-66 was evaluated. The results showed that adsorption was comparable with the experiments using non-active molybdenum and that the ^99mTc elution efficiency of around 70% could be achieved without zirconium breakthrough.

In order to determine the potential of ^177mLu/¹⁷⁷Lu radionuclide generator in ¹⁷⁷Lu production it is important to establish the technical needs that can lead to a clinically acceptable ¹⁷⁷Lu product quality. In this work, a model that includes all the processes and the parameters affecting the performance of the ^177mLu/¹⁷⁷Lu radionuclide generator has been developed. The model has been based on the use of a ligand to complex ^177mLu ions, followed by the separation of the freed ¹⁷⁷Lu ions. The dissociation kinetics of the Lu-ligand complex has been found to be the most crucial aspect governing the specific activity and ^177mLu content of the produced ¹⁷⁷Lu. The dissociation rate constants lower than 1*10^-11 s^-1 would be required to lead to onsite ¹⁷⁷Lu production with specific activity close to theoretical maximum of 4.1 TBq ¹⁷⁷Lu/mg Lu and with ^177mLu content of less than 0.01%. Lastly, the calculations suggest that more than one patient dose per week can be supplied for a period of up to 7 months on starting with the ^177mLu produced using 3 g Lu₂O₃ target with 60% ¹⁷⁶Lu enrichment. The requirements of the starting ^177mLu activity production needs to be adapted depending on the required patient doses, and the technical specifications of the involved ^177mLu-¹⁷⁷Lu separation process.

A solid phase extraction based ^177mLu-¹⁷⁷Lu separation method has been investigated for its feasibility to be used in the radionuclide generator. The use of 2,2′,2”-(10-(2,6-dioxotetrahydro-2H-pyran-3-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid, (DOTAGA-anhydride) allowed grafting of DOTA (1,4,7,10-tetraazacyclododecane N,N′,N″,N‴-tetraacetic acid) complex on the surface of commercially available amino propyl silica. The grafting of DOTA has been confirmed by several characterization techniques. The thermogravimetric analysis reveals that the 0.33 mmol DOTA groups have been grafted per gram of silica. However, during the Lu ion complexation, a 10 times lower Lu adsorption capacity of 0.03 mmol g⁻¹ could be achieved under the studied reaction conditions. The results indicate that the grafting of DOTA on solid affects the Lu coordination and also influences the kinetics of Lu-DOTA complexation. The weak coordination resulted in high ^177mLu leakage, while the unreacted DOTA groups interfer with the ¹⁷⁷Lu release. This is evident from the 0.3% ^177mLu leakage combined with a¹⁷⁷Lu extraction efficiency of 25%. Overall, the results show a^177mLu-¹⁷⁷Lu separation with a maximum ¹⁷⁷Lu/^177mLu activity ratio of 25. But this is still far away from clinically acceptable activity ratio of 10,000 for which future work is recommended.

In this work, ^177mLu has been produced by irradiation of natural Lu₂O₃ targets at the BR2 reactor (Mol, Belgium) and the obtained data together with literature values have been used to theoretically investigate the production of ^177mLu at different neutron fluxes, irradiation times and enrichment of ¹⁷⁶Lu. The irradiation time (t_max) needed to reach the maximum ^177mLu production has been found to change from 42, 12, 4 days with the increase in the thermal neutron flux from 2*10¹⁴, 8*10¹⁴, 2.5*10¹⁵ n cm⁻² s⁻¹, respectively while keeping the maximum ^177mLu activity unaffected. The results of our calculations suggest that 0.11 TBq ^177mLu with a specific activity of 0.3 TBq g⁻¹ Lu can be produced in a short irradiation time of 4 days using 1g of 84.44% ¹⁷⁶Lu enriched Lu₂O₃ and a thermal neutron flux of 2.5*10¹⁵ n cm⁻² s⁻¹.

Cu-based metal-organic framework (MOF) microdevices are applied in sampling and preconcentration of nerve agents (NAs) diluted in gaseous streams. An in situ electrochemical-assisted synthesis of a Cu-benzene-1,3,5-tricarboxylate (BTC) thick film is carried out to functionalize a Cu-modified glass substrate. This simple, rapid, reproducible, and easy-to-integrate MOF synthesis approach enables the microfabrication of functional micro-preconcentrators with a large Brunauer-Emmett-Teller (BET) surface area (above 2000 cm2) and an active pore volume (above 90 nL) for the efficient adsorption of nerve agent molecules along the microfluidic channel 2.5 cm in length. The equilibrium adsorption capacity of the bulk material has been characterized through thermogravimetric analysis after exposure to controlled atmospheres of a sarin gas surrogate, dimethyl methylphosphonate (DMMP), in both dry and humid conditions (30% RH at 293 K). Breakthrough tests at the ppm level (162 mg/m3) reveal equilibrium adsorption capacities up to 691 mg/g. The preconcentration performance of such μ-devices when dealing with highly diluted surrogate atmosphere, i.e., 520 ppbV (2.6 mg/m3) at 298 K, leads to preconcentration coefficients up to 171 for sample volume up to 600 STP cm3. We demonstrate the potentialities of Cu-BTC micro-preconcentrators as smart first responder tools for "on-field" detection of nerve agents in the gas phase at relevant conditions.

Hybrid materials bearing organic and inorganic motifs have been extensively discussed as playgrounds for the implementation of atomically resolved inorganic sites within a confined environment, with an exciting similarity to enzymes. Here, we present the successful design of a site-isolated mixed-metal metal organic framework (MOF) that mimics the reactivity of soluble methane monooxygenase enzyme and demonstrates the potential of this strategy to overcome current challenges in selective methane oxidation. We describe the synthesis and characterization of an Fe-containing MOF that comprises the desired antiferromagnetically coupled high-spin species in a coordination environment closely resembling that of the enzyme. An electrochemical synthesis method is used to build the microporous MOF matrix while integrating the atomically dispersed Fe active sites in the crystalline scaffold. The model mimics the catalytic C-H activation behavior of the enzyme to produce methanol and shows that the key to this reactivity is the formation of isolated oxo-bridged Fe units.

Photothermal therapy (PTT) and photodynamic therapy (PDT) both utilize light to induce a therapeutic effect. These therapies are rapidly gaining importance due to the noninvasiveness of light and the limited adverse effect associated with these treatments. However, most preclinical studies show that complete elimination of tumors is rarely observed. Combining PDT and PTT with chemotherapy or radiotherapy can improve the therapeutic outcome and simultaneously decrease side effects of these conventional treatments. Nanocarriers can help to facilitate such a combined treatment. Here, the most recent advancements in the field of photochemotherapy and photoradiotherapy, in which nanocarriers are employed, are reviewed.

Chemical clocks are often used as exciting classroom experiments, where an induction time is followed by rapidly changing colours that expose oscillating concentration patterns. This type of reaction belongs to a class of nonlinear chemical kinetics also linked to chaos, wave propagation and Turing patterns. Despite its vastness in occurrence and applicability, the clock reaction is only well understood for liquid-state processes. Here we report a chemical clock reaction, in which a solidifying entity, metal-organic framework UiO-66, displays oscillations in crystal dimension and number, as shown by X-ray scattering. In rationalizing this result, we introduce a computational approach, the metal-organic molecular orbital methodology, to pinpoint interaction between the tectonic building blocks that construct the metal-organic framework material. In this way, we show that hydrochloric acid plays the role of autocatalyst, bridging separate processes of condensation and crystallization.

Three supramolecular isomers of lutetium metal-organic framework, {Lu₂(H₂O)₄(ATA)₃·4H₂O}_n (Lu-ATA@RT), {Lu₂(H₂O)₂(C₃H₇NO)₂(ATA)₃}_n (Lu-ATA@100), and {Lu₂(C₃H₇NO)(ATA)₃}_n (Lu-ATA@150), have been obtained from the reaction of Lu(NO₃)₃·6H₂O with 2-aminoterephthalic acid (ATA) at different temperatures. The resulting structures of Lu-ATA metal-organic frameworks depend on the temperature applied during the synthesis, revealing a temperature-susceptible supramolecular isomerism. Single-crystal X-ray diffraction analyses suggest that new compounds with formula {Lu₂(S)_x(ATA)₃}_n (S = solvent: H₂O, DMF) display different three-dimensional architectures which consist of dinuclear lutetium building units. The supramolecular isomer Lu-ATA@RT, formed at room temperature, has a pcu-net topology, while its double interpenetrated analogue Lu-ATA@100 assembles at 100 °C under hydrothermal conditions. Hydrothermal synthesis at 150 °C affords formation of the dense Lu-ATA@150 cage-like framework displaying a new hexagonal-packed net topology. All Lu-ATA isomeric phases are porous and display different gas-uptake behavior toward carbon dioxide as a function of polymeric network arrangement. The luminescent properties of Lu-ATA frameworks in the solid state as well as in suspension in the presence of different solvents reveal a solvent-dependent emission.