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Anionic liposomes (AL) are very attractive for nanomedicine and some formulations have already been launched for clinical development. Despite the excellent potential, their application presents two major challenges: laborious production methods and rapid degradation and elimination from blood by the immune system. In this work, we optimized the production of AL and its stealth form (SAL) using a onestep microfluidic process. We obtained unilamellar and near-monodisperse (10%) AL composed by the commercial composition (DMPC:DMPG) with mean size small as 53.7 nm, which is optimized for application in drug delivery. We also obtained SAL with similar characteristics using the microfluidic technique, overcoming the limitation of conventional methods where SAL presents high polydispersity (30%). This study demonstrates the great potential of the microfluidic technique for one-step production of stealth anionic nanoliposomes with controlled sizes and reproducible characteristics.

In the present study, we tested the proof of concept that mobil mesoporous silica nanoparticle composition of matter (MCM) No. 48 doped with trivalent europium (nanoMCM48:Eu3+) administered systemically intravenously can act as a suitable vehicle to deliver neural cells to the brain of healthy adult Swiss mice without causing tissue damage. Moreover, we also tested the ability of this nanoparticle to release molecules in vitro, using as drug models caffeine or nicotine in phosphate buffer solution with pH 7.4 adequate to intra and extra-celular medium of the brain. The caffeine and nicotine adsorbed nanoparticles (CAF@MCM48:Eu3+ and NIC@MCM48:Eu3+) were observed in the parenchyma of the cerebral cortex and diffusely dispersed in the cellular cytoplasm. Statistical analysis using multivariate partner recognition methods indicated that there was no sign of cell damage, as it was characterized by chromatin condensation, nuclear condensation, or fragmentation. The characterization of nanoMCM48:Eu3+ as particle size, luminescent properties and release of active components were analyzed. The CAF@MCM48:Eu3+ and NIC@MCM48:Eu3+ nanoparticles were observed in the cerebral cortex parenchyma and diffusely dispersed in the cell cytoplasm, and the release of active components was analyzed. Therefore, the studies showed that mesoporous silica nanoparticles administered systemically via intravenous tissue can act as a suitable vehicle for neural cells in the brain of healthy mice without causing damage.

Background: Unfinished root formation has always offered challenges in endodontics due to technical difficulties and weakened teeth resistance during the lifetime of an individual. Pulp revascularization therapy appeared as a solution for apical closure and root maturation. The existence of oral stem cells involved in the process associated with traditional resident cells requires adequate blood supply given by induced controlled injury deliberately accomplished into the periapical zone. Objective: The aim of this work was to research, through literature review, the main mechanisms involved in the process of apical closure through the technique of pulp revascularization. Conclusion: Apice closure in pulpless teeth seems to happen as a result of professional intervention and biological activity. The success rate depends on the role of traditional local immune cells and stem cells associated with adequate blood supply to finish root formation.

Chagas disease (CD), caused by the flagellate protozoan Trypanosoma cruzi, is one of the major public health problems in developing countries. Benznidazole (BNZ) is the only drug available for CD treatment in most countries, however, it presents high toxicity and low bioavailability. To address these problems this study used Zeolitic Imidazolate Framework-8 (ZIF-8), which has garnered considerable attention due to its potential applications, enabling the controlled delivery of drugs. The present work developed and characterized a BNZ@ZIF-8 system, and the modulation of BNZ release from the ZIF-8 framework was evaluated through the in vitro dialysis release method under sink conditions at different pH values. Moreover, the in vitro evaluation of cell viability and cytotoxicity by MTT assay were also performed. The dissolution studies corroborated that a pH sensitive Drug Delivery System capable of vectorizing the release of BNZ was developed, may leading to the improvement in the bioavailability of BNZ. The MTT assay showed that no statistically significant toxic effects occurred in the developed system, nor significant effects on cell viability.

Colorectal cancer is one of the most significant types of cancer, ranking second in the world’s mortality cases. As colorectal cancer is often diagnosed at a late stage of disease progression, effe...

The metal-organic framework (MOF) [Eu(DPA)(HDPA)] (where DPA is dipicolinic acid) has been previously reported as an efficient marker for gunshot residues (GSRs). Since this marker will be in contact with various shooters, industrial workers, and the environment, however, it is important to identify its toxicity. In this work, the oral and the inhalation acute toxicities of the MOF [Eu(DPA)(HDPA)] (also called R-Marker) were evaluated in young Wistar rats using Guidelines 423 (oral) and 436 (inhalation) from the Organisation for Economic Co-operation and Development (OECD). Animal behavior; body weight, water, and food intake; and organ weight, as well as biochemical parameters were evaluated in both evaluations. For the inhalation test, a concentration of 1 mg·L

In this investigation, the influence of gamma radiation in a therapeutic dose, such as the dose generally administered (on average) in two cycles of radiotherapy treatment, was evaluated for the chemical characteristics of nanocomposite films formed by polycaprolactone (PCL) with oxide nanoparticles of ZnO (ZnO NPs). The PCL nanocomposite films with ZnO NPs (PCL/ZnO NCs) were obtained via solvent casting method, using chloroform as solvent, with ZnO NPs mass contents in relation to polymer masses equal to: 02%; 0.4%; 0.6%; 0.8% and 1.0%. After this step, the films obtained were exposed to gamma radiation in a dose of 140 Gy in the presence of air and at room temperature. The influence of gamma radiation in a therapeutic dose on the chemical characteristics of nanocomposite films obtained through the solvent casting method, was accessed through absorption spectroscopy in the infrared region. Our results indicate that the chemical structure of PCL is preserved after exposure to gamma radiation at 140 Gy. En esta investigación se evaluó la influencia de la radiación gamma sobre la dosis terapéutica, como la dosis habitualmente utilizada (en promedio) en dos ciclos de tratamiento de radioterapia, sobre las características químicas de películas de nanocompuestos formadas por policaprolactona (PCL) con nanopartículas de óxido de ZnO (NP de ZnO). Las películas de nanocompuestos de PCL con NP de ZnO (PCL / ZnO NC) se obtuvieron mediante el método de fundición por solvente, utilizando cloroformo como solvente, con contenidos de masa de ZnO NP en relación a la masa de polímero igual a: 02%; 0,4%; 0,6%; 0,8% y 1,0%. Tras este paso, las películas obtenidas se expusieron a radiación gamma a una dosis de 140 Gy en presencia de aire y a temperatura ambiente. Se accedió a la influencia de la radiación gamma en dosis terapéutica sobre las características químicas de películas de nanocompuestos obtenidas mediante el método de fundición con solvente, mediante espectroscopía de absorción en la región infrarroja. Nuestros resultados indican que la estructura química del PCL se conserva después de la exposición a radiación gamma a 140 Gy. Nesta investigação, a influencia da radiação gama em dose terapeutica, como por exemplo, a dose costumeiramente utilizada (em media) em dois ciclos de tratamento radioterápico, foi avaliada sobre as características químicas de filmes de nanocompósitos formados pela policaprolactona (PCL) com nanopartículas de óxido de ZnO (ZnO NPs). Os filmes de nancompósitos da PCL com ZnO NPs (PCL/ZnO NCs) foram obtidos através do método de solvent casting, utilizando clorofórmio como solvent, com teores em masa de ZnO NPs em relação a massa do polímero iguais a: 02%; 0.4%; 0.6%; 0.8% e 1.0%. Apos essa etapa os filmes obtidos foram expostos a radiação gama na dose de 140 Gy em presenca de ar e em temperatura ambiente. A influência da radiação gama em dose terapeutica nas caracterísiticas químicas dos filmes de nanocompósitos obtidos através do médoto de solvent casting, foi acessada através da espectroscopia de absorção na região do infravermelho. Nossos resultados indicam que a estrutura química da PCL é preservada após a exposição a radiação gama em 140 Gy.

Nowadays, emerging radiolabeled nanosystems are revolutionizing medicine in terms of diagnostics, treatment, and theranostics. These radionuclides include polymeric nanoparticles (NPs), liposomal carriers, dendrimers, magnetic iron oxide NPs, silica NPs, carbon nanotubes, and inorganic metal-based nanoformulations. Between these nano-platforms, polymeric NPs have gained attention in the biomedical field due to their excellent properties, such as their surface to mass ratio, quantum properties, biodegradability, low toxicity, and ability to absorb and carry other molecules. In addition, NPs are capable of carrying high payloads of radionuclides which can be used for diagnostic, treatment, and theranostics depending on the radioactive material linked. The radiolabeling process of nanoparticles can be performed by direct or indirect labeling process. In both cases, the most appropriate must be selected in order to keep the targeting properties as preserved as possible. In addition, radionuclide therapy has the advantage of delivering a highly concentrated absorbed dose to the targeted tissue while sparing the surrounding healthy tissues. Said another way, radioactive polymeric NPs represent a promising prospect in the treatment and diagnostics of cardiovascular diseases such as cardiac ischemia, infectious diseases such as tuberculosis, and other type of cancer cells or tumors.

TNF-α is a member of the vast cytokine family being considered a proinflammatory substance produced many by macrophages and other cells belonging to the innate immunity, many of them classified as indeed Antigen Presenting Cells (APCs) involved in the complex chemotactic process of activation of the adaptive immunity. The aim of this work was to accomplish a literature review concerning the main pathologies that have TNF-α as a modulating agent in other to bring light to the main interactions present in the inflammation installed.

An adsorbent-heater-thermometer nanomaterial, (ZIF-8,EuxTby)@AuNP, based on ZIF-8 (adsorbent), containing Eu3+ and/or Tb3+ ions (thermometer) and gold nanoparticles (AuNPs, heater) was designed, synthetized, characterized, and applied to controlled drug release. These composite materials were characterized as core-shell nanocrystals with the AuNPs being the core, around which the crystalline ZIF-8 has grown (shell) and onto which the lanthanide ions have been incorporated or chemosorbed. This shell of ZIF-8 acts as adsorbent of the drugs, the AuNPs act as heaters, while the luminescence intensities of the ligand and the lanthanide ions are used for temperature monitoring. This thermo-responsive material can be activated by visible irradiation to release small molecules in a controlled manner as established for the model pharmaceutical compounds 5-fluorouracil and caffeine. Computer simulations and transition state theory calculations shown that the diffusion of small molecules between neighboring pores in ZIF-8 is severely restricted and involves high-energy barriers. These findings imply that these molecules are uploaded onto and released from the ZIF-8 surface instead of being inside the cavities. This is the first report of ZIF-8 nanocrystals (adsorbents) containing simultaneously lanthanide ions as sensitive nanothermometers and AuNPs as heaters for controlled drug release in a physiological temperature range. These results provide a proof-of-concept that can be applied to other classes of materials, and offer a novel perspective on the design of self-assembly multifunctional thermo-responsive adsorbing materials that are easily prepared and promptly controllable.

We have reported the use of luminescent metal-organic frameworks for the development of a new alternative for UV-B radiation sensing. For obtaining the sensor, a doping sequence of Europium (1%, 2%, and 5%) was performed on the Zn(BDC)(dpNDI)(DMF) using solvothermal synthesis. The final material was characterized using powder X-ray diffraction (PXRD), Infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and spectroscopic investigation. The sensing phenomenon was studied from the controlled exposure of the Zn(BDC)(dpNDI):2% Eu coordinating polymer (without DMF in the structure) under UV-B radiation. Analysis of PXRD revealed that materials Zn(BDC)(dpNDI)(DMF): x% Eu (x = 1, 2 and 5%) show maintenance of the original MOF structure after incorporation of Eu3+ ion. The results of FT-IR indicate that Europium is connected in the compound by coordination bonds, evidenced by a detailed analysis of the symmetrical and asymmetric stretching of the ligand carbonyl group. The spectroscopic analysis for the material assisted in the realization of the correlation between the proposed structure and the environment occupied by the lanthanide ion. The sensing properties were studied for the compound Zn(BDC)(dpNDI):2%Eu mainly by the evaluation of the emission spectrum. The compound showed a significant decrease in its emission intensity after exposure to the UV-B radiation dose (0-9 J.cm-2), a phenomenon that has been explored in the composition of the sensor. The sensing mechanism was estimated through the analysis of ultraviolet-visible absorption spectrum and reflectance spectra in the determination of its direct and indirect band gap. Finally, the compound Zn(BDC)(dpNDI):2%Eu presented a versatile material for the development of tunable emitter material (exhibiting white light emission) and a promising dosimetric sensor of UV radiation light.

Benzene, toluene, ethylbenzene, and xylenes (BTEX), a class of volatile organic compounds, are harmful pollutants but also very important precursors in organic industrial chemistry. Among different approaches used for the BTEX treatment, the adsorption technology has been recognized as an efficient approach because it allows to recover and reuse both adsorbent and adsorbate. However, the selective adsorption of the components is the key factor for the efficiency of the process. With this view, calixarene-based materials are very promising due to the unique cavity-like structure of the ligand. An unprecedented coordination network based on calixarene of an interesting nanosheet-like morphology was prepared via a solvothermal layer method. This material showed selectivity for non-polar molecules with remarkable uptake of benzene (38.33 mmol/g). In addition, a simple and useful method of BTEX quantification, through 13 C NMR spectroscopy, is reported here for the first time.

In this work, a multifunctional system was developed in which antibacterial and luminescent properties were inserted into the matrix of hydroxyapatite (HAp) and its efficiency as a support for an antineoplastic drug was evaluated, aiming its application in the treatment of osseous diseases. The precipitation method was used for the synthesis of HAp, EuCl3 was used for the incorporation of Eu3+ as imaging agents, silver nanoparticles (AgNPs) with antimicrobial function were used, and a model of drug, 5-fluorouracil (5FU) was used. The developed material is characterized by several techniques, where crystalline peaks attributed to HAp were identified in the X-ray diffractogram, whereas the luminescence spectrum of the material presented emissions attributed to the Eu3+ ion. The identification and the uniform distribution of AgNPs, 5FU, and Eu3+ were confirmed by mapping the sample using energy-dispersive spectroscopy. The measurements indicated that 82% (±2.8) of 5FU was incorporated into the HAp matrix, and a gradual and increasing release of it as a function of time was observed. Assays carried out for different bacteria confirmed the antimicrobial action of the samples and the efficiency of the drug inserted into the matrix. An in vitro assay showed the bioactivity of the material and its potential to bind to living osseous tissue.

We show that filamentous fungi can emit green or red light after the accumulation of particulate lanthanide metal-organic frameworks over the cell wall. These new biohybrids present photoluminescence properties that are unaffected by the components of the cell wall. In addition, the fungal cells internalise lanthanide metal-organic framework particles, storing them into organelles, thereby making these materials promising for applications in living imaging studies.

Herein we present a synthesis of ionic liquid imidazole-based cations with appended sulfone as terminals. These structures are investigated by RMN (2D), XDR, FTIR and Raman; and show high yield; purity; melting point 1.6 ms, quantum efficiency > 77%, narrow linewidth, a high degree of color purity and tunable emission. These excellent photophysical properties, associated with soft materials processability, make these materials potentially applicable in the development of luminescent films as OLEDs. We provide data for a detailed study of photoluminescence based on the theories developed by Malta-Judd-Ofelt. © 2018 Elsevier Science. All rights reserved

Here, we report the preparation and characterization of stable AgIn5Te8 (AITe) nanocrystals (NCs) and their respective AITe–ZnS and AITe–ZnSe alloys. A green route of synthesis is described by using an aqueous electrochemical method in a cavity cell. The elemental ratio modulation of the NCs was investigated to determine the ideal improvement of the structural and electronic properties. The AITe NCs presented an emission band at 889 nm and hypsochromic shifts when coated with ZnS and ZnSe seeds. Photothermal analyses point to theranostic applications.

Chagas disease is a neglected tropical disease caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi). Endemic in underdeveloped and developed countries, due to the migratory movement, it is considered a serious public health problem. Endemic in underdeveloped countries and due to the migratory movement, in developed countries as well, it is considered a serious public health problem. One of the reasons for this is a weak therapeutic arsenal, represented only by the drug benznidazole (BNZ) which, although it promotes significant cure rates in the acute phase of the disease, presents serious problems of toxicity and bioavailability, mainly due to its low aqueous solubility. Several studies have presented several drug delivery systems (DDS) based on BNZ aiming at enhancing its solubility in aqueous medium and, with this, promoting an increase in the dissolution rate and, consequently, in its bioavailability. However, the present work is a pioneer in using a zeolitic imidazolate framework as a carrier agent for a DDS in order to promote a pH-sensitive modulation of the drug. Thus, this work aimed to develop a novel DDS based on BNZ and the ZIF-8 to use it in development of prolonged-release dosage forms to alternative treatment of Chagas disease. The BNZ@ZIF-8 system was obtained through an ex situ method selected due to its higher incorporation efficiency (38%). Different characterization techniques corroborated the obtainment and drug release data were analyzed by in vitro dissolution assay under sink and non-sink conditions and setting the kinetic results through both model dependent and independent methods. Under sink conditions, at pH 4.5, BNZ and BNZ@ZIF-8 showed similar release profile, but the DDS was effective in promoting a prolonged release. At pH 7.6, after 7 h, BNZ showed a lower release than BNZ@ZIF-8. On the other hand, in non-sink conditions at pH 4.5 the BNZ presented 80% of drug release in 3 h, while the DDS in 6 h. At pH 7.6, BNZ presented a release of 80% in 2 h, while the DDS reaches it in only at 12 h. Therefore, at pH 4.5 the DDS BNZ@ZIF-8 showed a faster release with a burst effect, while at pH 7.6 it showed a prolonged and controlled release. Finally, it is evident that a promising DDS pH-sensitive was obtained as a novel carrier that might be able to prolongs BNZ release in dosage forms intended for the alternative treatment of Chagas disease.

International audience; Golden grass is a vegetal fiber used in arts and crafts for its peculiar optical properties, namely, its shiny golden-like reflectivity. Since vegetal fiber structure is usually heterogeneous, complementary techniques have been used to understand the electronic properties of the external and core regions of golden grass fibers. The composition and dielectric function of the few nanometer-thick external surfaces has been investigated using X-ray photoelectron spectroscopy and energy loss spectroscopy (XPS-PEELS), while a comparison of vibrational and optical properties of the few-micron-thick external and fiber core regions was derived from Raman, optical, photoluminescence (PL) and photoacoustic (PAS) spectroscopies. Raman signature and valence-band distribution indicate that the internal and external parts of the fibers are made of some oxygen-depleted lignin-like carbonaceous material. Besides a plasmon peak at 21 eV, two main absorption bands at 3.7 eV and 8.2 eV have been identified as π−π* and σ−σ* electronic transitions at aromatic moieties. PL excitation and emission behavior confirm heterogeneous molecular structures at the core and external regions. Specular reflectance spectra calculated from the complex refractive index (derived from XPS-PEELS) do not explain the shiny golden-like aspect of golden grass, which may arise from diffuse reflectance within a collection of heterogeneous hollow fibers.

Two lanthanide complexes supported on MCM48 type silica have been synthetized to introduce a new concept of multi-stimuli responsive materials for anti-counterfeiting applications. This new technology provides a simple and secure way of storing information with different levels of security from biocompatible materials. Different luminescent patterns can be revealed and suppressed by external stimuli: addition and removal of a specific reagent (chemical stimulus) followed by UV exposure to reveal the characteristic luminescence of the material and heat treatment (physical stimulus) to suppress the red luminescence of the material. The chemical stimulus occurs from the complexation of β-diketone 4,4,4-trifluoro-1-phenyl-1,3-butadione (BTFA) in the Eu(H2O)nL–SiO2 (L = chelidamic acid or trimesic acid) printed hybrid and can be made via insertion of the ligand by soaking the label using a marker pen. Physical stimuli can occur through a portable heat gun. The complexation with BTFA enhances the Eu-luminescence through the antenna effect under exposure to common UV-light. Heating (∼145 °C) for a few seconds rapidly quenches the luminescence of the label and, after some cycles of heating–cooling, BTFA sublimates and leads to complete quenching of the red luminescence. The combination of chemical and physical stimuli provides two levels of security verification and unbreakable encryption.

In this work, we report the synthesis of a new 1,3-thiazolium-5-thiolate derivative of a mesoionic compound (MIH 2.4Bl) and the characterization of its selective cytotoxicity on a panel of breast cancer cells lines. The cytotoxic effect of MIH 2.4Bl on breast cancer cell lines was determined by XTT and crystal violet assays, flow cytometry analysis, electron microscopy characterization, and terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) apoptosis assays. As determined using XTT cell growth and survival assays, MIH 2.4Bl exhibited growth inhibition activity on most breast cancer cell lines tested, compared with normal human mammary epithelial cells. Three breast cancer cell lines (MCF-7, T-47D, and ZR-75-1) showed a more potent sensitivity index to growth inhibition by MIH 2.4Bl than the other breast cancer cell lines. Interestingly, these 3 cell lines were derived from tumors of Luminal A origin and have ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2) positive expression. Additional analysis of cytotoxicity mediated by MIH 2.4Bl was performed using the MCF-7 cell line. MCF-7 cells displayed both time- and dose-dependent decreases in cell growth and survival, with a maximum cytotoxic effect observed at 72 and 96 hours. The MCF-7 cells were also characterized for cell cycle changes upon treatment with MIH 2.4Bl. Using flow cytometry analysis of cell cycle distribution, a treatment-dependent effect was observed; treatment of cells with MIH 2.4Bl increased the G2/M population to 34.2% compared with 0.1% in untreated (control) cells. Ultrastructural analysis of MFC-7 cells treated with MIH 2.4Bl at 2 different concentrations (37.5 and 75 μM) was performed by transmission electron microscopy. Cells treated with 37.5 μM MIH 2.4Bl showed morphologic changes beginning at 6 hours after treatment, while cells treated with 75 μM showed changes beginning at 3 hours after treatment. These changes were characterized by an alteration of nuclear morphology and mitochondrial degeneration consistent with apoptotic cell death. Results of a TUNEL assay performed on cells treated for 96 hours with MIH 2.4Bl supported the observation of apoptosis. Together, these results suggest that MIH 2.4Bl is a promising candidate for treating breast cancer and support further in vitro and in vivo investigation.

Background: Acquired Immunodeficiency Syndrome (AIDS) is a major public health problem in the world. One of the highly effective drugs in anti-HIV therapy is efavirenz (EFZ), which is classified as Class II according to the Classification System of Biopharmaceuticals, presenting low solubility and high permeability, this being an obstacle related to the drug. Objective: This study aimed to obtain an innovative system based on EFZ and the Zeolitic Imidazolate Framework (ZIF-8) to use in the development of prolonged-release pharmaceutical forms that can circumvent this problem. Methods: The EFZ: ZIF-8 system was obtained by a selected ex-situ method due to its higher incorporation efficiency. Different characterization techniques corroborated the obtainment of the system, and drug release was analyzed by dissolution testing under sink conditions, the profiles being adjusted to some kinetic models. Results: At pH 1.2, the structure of ZIF-8 breaks down rapidly, releasing a large amount of drug within either 3h or short time. In the pH 4.5 and 6.8 medium, the EFZ release from the EFZ: ZIF-8 system obtained in ethanol was prolonged, releasing 95% of the drug in 24h at pH 4.5 and 75% medium at pH 6.8. Conclusion: It is evident that a promising pH-sensitive system was obtained using ZIF-8 as a novel carrier of EFZ intended for the alternative treatment of AIDS.

Polyaniline-decorated ZIF-8 nanoparticles (nPANI@nZIF-8) were easily synthesized and employed as a multifunctional system for the delivery of the antitumor drug 5-fluorouracil (5-FU). Because of the storage ability of the network ZIF-8, 68% of the total amount of the 5-FU drug was released at pH 5.2. The system exhibits absorption in the near-infrared (NIR) region and can be used in the photothermal therapy owing to the presence of nPANI, which has a strong NIR uptake. This absorption causes local hyperthermia by aiding in the diffusion of the drug molecules contained by the polymer into nPANI@nZIF-8/5-FU achieving a greater release of the 5-FU drug, about 80% activated by an NIR laser (λ = 980 nm). This hyperthermia reached about 70 °C (200 μL, 1 mg mL–1 nPANI@nZIF-8), which was directly proportional to the concentration of the material. Therefore, our work can aid in the construction of new chemo-photothermal platforms that may be employed in cancer therapy.

The metal-organic framework [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ was synthetized and characterized by X-ray diffractometry, differential thermogravimetric analysis, and infrared spectroscopy. The material was tested for the development and validation of a matrix solid-phase dispersion procedure for extraction of atrazine, bifenthrin, bromuconazole, clofentezine, fenbuconazole, flumetralin, procymidone, and pirimicarb, from peppers, with analysis using gas chromatography with mass spectrometry in the selected ion monitoring mode. The method developed was linear over the range tested (50.0-1000.0 μg/kg for procymidone and 200.0-1000.0 μg/kg for all other pesticides), with correlation coefficients ranging from 0.9930 to 0.9992. Experiments were carried out at 250.0, 500.0, and 1000.0 μg/kg fortification levels, and resulted in recoveries in the range of 52.7-135.0%, with coefficient of variation values between 5.2 and 5.4%, respectively, for [(La0.9 Sm0.1 )2 (DPA)3 (H2 O)3 ]∞ sorbent. Detection and quantification limits ranged from 16.0 to 67.0 μg/kg and from 50.0 to 200.0 μg/kg, respectively, for the different pesticides studied. The results were compared with literature data. The developed and validated method was applied to real samples. The analysis detected the presence of residues of pesticides procymidone, fenbuconazole, flumetralin, clofentezine, atrazine, and bifenthrin.

Mixed lanthanide-organic frameworks (MLOFs) are an interesting class of hybrid materials with unique luminescence properties. The detailed structure–property relationship studies are still insufficient and therefore, the precise design and synthesis of these materials are still required. With this view, MLOFs based on Gd3+, Eu3+ and Tb3+ ions and terephthalate were synthesized under solvothermal conditions, and the influence of the Eu3+ dopant concentration on the photophysical properties of Gd/Eu-1,4-BDC-MOFs was studied. Moreover, the effect of the excitation wavelength on color tuning in a Gd/Tb/Eu-1,4-BDC-MOF co-doped sample is also discussed here. Analyses of X-ray diffraction data indicated the Gd/Eu-1,4-BDC single phase formation in samples doped up to 7 mol% of Eu3+ ions. By increasing the europium content, a second crystalline phase was formed. Both crystalline phases with a metal–organic structure exhibited a red luminescence due to the characteristic 4f–4f transitions of Eu3+ ions. Although not observed in the X-ray diffraction patterns, most probably the second phase was also present in the sample with 7 mol% of Eu3+ ions, based on the results of photoluminescence. The Gd/Eu/Tb-1,4-BDC co-doped sample with 2.5 mol% of Eu3+ and 2.5 mol% of Tb3+ obtained as a single phase exhibited both red and green emissions due to the presence of Eu3+ and Tb3+ ions, respectively. Furthermore, the spectroscopic analysis indicated the energy transfer from Tb3+ to Eu3+, which allows the color tuning by changing the excitation wavelength.

Herein, we describe for the first time room temperature ionic liquids (RTILs) and imidazole-based cations with appended carboxylic acids as terminals, which are directly derived from the anhydrides. All structures were designed to meet the following criteria: (1) easy preparation (up-scaling into kg scale possible); (2) melting point of 1 ms, high quantum efficiency (47%), featured quantum yield (27%), and a remarkable sensitization efficiency to ILs of up to 83%, which suggests a synergistic coordination with lanthanide ions. We show that the materials obtained are potentially applicable for the construction of light-emitting electrochemical cells, owing to the properties of their basic components, including ionic liquids (with high electrical conductivity and a similar structure to liquid crystals) and lanthanide ions (which have unprecedented photophysical properties).

Analysis of gunshot residues (GSR) is a vital point of interest in forensic chemistry. GSR analysis is very well established, but there is still a lack of methodology to identify GSR obtained from lead-free or ‘non-toxic ammunition’ (NTA). To identify GSR from NTA, we have proposed the incorporation of luminescent markers to provide an optical and chemical signature to GSR. Furthermore, the luminescent markers can open up prospectives for ammunition encoding by adjusting their composition. Herein, we report the distinction among GSR particles containing different MOF-based markers by analyzing their organic fractions using near-infrared hyperspectral imaging (NIR-HSI) together with multivariate analysis (MCR-ALS). The method has been proven to be effective, non-destructive and fast in distinguishing marked GSR. It is possible to detect and correctly identify 72.2% of the samples, and all cases of misclassification are related to slight amount of material collected (8.3%) or confusion caused by one of the markers (19.4%). The study is developed in a forensic context of GSR analysis; however, the methodology described here is excellent and can be extrapolated to other applications that require distinguishing MOFs with different ligands.

In this work, reduced Titania (TiO2−x) was obtained by laser ablation of commercial rutile TiO2 powder dispersed in N,N-dimethyl formamide (DMF) using a pulsed Nd:YAG (Neodymium-doped Yttrium Aluminium Garnet) laser (532 nm, 10 ns, 10 Hz). It was observed that DMF solvent was able to promote change in the optical band gap of commercial TiO2 (P25). The Ultraviolet–Visible (UV–vis) absorption measurement showed a shoulder in the infrared region with maximum at 690 nm, characteristic of reduced metal oxide. The electron paramagnetic resonance (EPR) measurements confirmed the presence of oxygen vacancies by the characteristic signal in g = 2.002 g and more intense than water-reduced oxide commonly obtained in other works. The X-ray diffraction (XRD) results show the same crystalline phase to P25 and small shifts due to presence of vacancy’s distorting the TiO2 structure. Scanning electron microscopy (SEM) image have shown surface coalesced particles in comparison to commercial P25, agreeing with nitrogen adsorption measurements which indicated a decrease in the surface area from 10.6 to 6.9 m2/g. The photothermal conversion properties was investigated and the reduced TiO2 samples showed higher temperatures when excited with a laser 785 nm wavelength in function of the strong absorption band and higher vacancy’s concentration.

We report in this work, a new method for the determination of captopril by differential pulse voltammetry using a glassy carbon electrode modified with a copper metal-organic framework (H-Kust-1 or Cu3(BTC)2 or Cu-BTC), immobilized on the surface by a copolymer of acrylamide and sodium acrylate. This compound is detected by the formation of a copper(II)-captopril complex that is observed in an oxidation potential at ca. +0.28 V vs. Ag/AgCl. A linear dynamic range is obtained for a captopril concentration of 0.5 μM to 7.0 μM and the voltammetric response is highly reproducible within 3.52 % error. The sensitivity of 9.71±0.37 nA μM−1 and the limit of detection of 0.20±0.01 μM make this methodology highly applicable for practical applications. The determination of captopril in a commercial pharmaceutical sample showed a recovery of 93.3 %.

Luminescent materials have been widely studied due to the increasing number of applications in catalysis, biosensors and electro-optical devices. In this sense, the improvement of luminescent efficiency has been sought and several strategies have been proposed. In this work, experimental and theoretical approaches were used to achieve and understand the improvement of luminescent efficiency of lanthanide organic frameworks through a heating process. In this study, [Eu 2 (MELL)(H 2 O) 6 ] (EuMELL) was synthesized and characterized by scanning electron and fluorescence microscopies, thermogravimetric analysis, powder X-ray diffraction and photoluminescence techniques. In parallel, theoretical simulations of the material in solid phase were carried out using semiempirical approaches. The comparison between experimental and theoretical results indicated that the more accurate structure was calculated using the Sparkle/PM3 model. The temperature effects on the structure as well as the photophysical properties were evaluated by measurements in situ heating and compared to theoretical simulations using the Sparkle/PM3 geometry. The excellent agreement between the computational and experimental results in this study opens up a series of possibilities for studying other systems, particularly when structural details are not easily available. Moreover, that the controlled heating contributes to improve its the quantum efficiency by approximately 45%, suggesting that this approach can be a valuable tool for technological applications.

A multifunctional smart supramolecular platform based on a lanthanide-organic hydrogel is presented. This platform, which provides unique biocompatibility and tunable optical properties, is synthesized by a simple, fast, and reproducible eco-friendly microwave-assisted route. Photoluminescent properties enable the production of coated light-emitting diodes (LED), unique luminescent barcodes dependent on the excitation wavelength and thin-films for use in tamper seals. Moreover, piroxicam entrapped in hydrogel acts as a transdermal drug release device efficient in inhibiting edemas as compared to a commercial reference.

The incorporation of drugs in biodegradable polymeric particles is one of many processes that controllably and significantly increase their release and action. In this paper, we describe the synthesis and physicochemical characterization of ZnBDC-MOF + doxorubicin (DOXO@ZnBDC) and the system's effectiveness in the sustained release of the drug doxorubicin. An experimental and theoretical study is presented of the interaction between the [Zn(BDC)(H2O)2]n MOF and the drug doxorubicin (DOXO). The synthesis was characterized by elemental analysis and X-ray powder diffraction (XRPD). The experimental incorporation was accomplished and analyzed by Fourier transform infrared spectroscopy (FTIR), XRPD and UV–Vis (ultraviolet–visible) spectrophotometry. Based on an analysis of the doxorubicin release profile, our results suggest that the drug delivery system showed slower release than other systems under development. Studies of cytotoxicity by the MTT method showed good results for the system developed with antineoplastic doxorubicin, and together with the other results of this study, suggest the successful development of a MOF-based drug delivery system.

The production of fatty acid methyl esther (FAME) via transesterification was studied, assessing the influence of CaO heterogeneous catalysts obtained from four different fishery residues: sururu, crab, clam and mussel. Characterization and properties of the residues were obtained via thermogravimetric analysis, X-ray diffraction, X-ray fluorescence, Fourier transform infrared (FTIR) spectra, nitrogen adsorption/desorption, chemical composition and scanning electron microscopy (SEM). Catalytic activities and reaction kinetics of FAME synthesis from the transesterification of soybean oil were performed. FAME yield was determined by 1H nuclear magnetic resonance (NMR). A higher efficiency and reaction rate were observed for the catalysts obtained from the sururu residues with 93.7% FAME yield after 3.5 h of reaction at the first usage, reducing only to 91.0% after four consecutive cycles of reuse. The best activities were assigned to the presence of SrO, to smaller particle size, higher pore volumes and the higher Ca leaching, yielding Ca-diglyceroxide which is an important active phase for transesterification.

Matrizes de hidroxiapatita (HAp) dopadas com os ions lantanideos Eu3+, Ce3+ e Gd3+, [Ca10-xLnx(PO4)6(OH)2], foram obtidas pelo metodo da precipitacao com o objetivo de estudar suas propriedades fotofisicas. A partir de analises de Microscopia Eletronica de Varredura observou-se que amostras dopadas com ions lantanideos (Ln3+) apresentaram similaridade com a morfologia da HAp pura, por outro lado nos difratogramas de Raios X a partir do refinamento Rietveld verificou-se que a matriz aparece como fase majoritaria (≈ 70%) enquanto (≈ 30%) de uma fase secundaria de tricalcio fosfato (TCP) foi conferida em funcao das diferentes dopagens. Isotermas de adsorcao obtidas pela tecnica BET indicaram que todos os materiais sintetizados sao classificados como mesoporosos. Os espectros de emissao dos materiais exibem bandas caracteristicas dos ions Ln3+ incorporados a estrutura da matriz em 573 nm (5D0→F0), 600 nm (5D0→F1), 628 nm (5D0→F2), e 698 nm (5D0→F4) para HAp/Eu, 337-360 nm (5d→4f) para HAp/Ce e em 425 nm para HAp/Gd. Palavras-chave: Hidroxiapatita; Composito; Luminescente; Biomaterial; Propriedades.

We have found that monosodium glutamate, a common food additive, combines with neodymium(III) chloride to form a gel-like luminescent material. Preliminary rheology tests suggest that arrested phase separation causes the material’s gel behavior at high test frequencies. Luminescence spectra showed not only the expected Nd3+ emissions (upon 582 nm excitation) but also a broad emission in the infrared with maximum on 980 nm (upon 289 nm excitation), preliminarily assigned to a matrix effect.

The elucidation of the action of doxorubicin (DOX) has been considered a challenge for cancer therapy. Using theoretical approaches, we investigated the structure and electronic properties of DOX as a function of pH, which we thought likely to be related to the influence of its tautomers. Regarding the relative stabilities among the tautomers, the results obtained from PM6 were the most similar to those obtained from DFT. The theoretical absorption spectrum for each tautomeric species simply showed a single absorption peak located around 400 nm, in contrast to the experimental absorption spectra in the literature that showed four absorption bands. The experimental evidence was properly explained by considering four tautomeric conformers of DOX. The spectroscopic study of the deprotonated tautomers also suggested the presence of four deprotonated tautomers at more basic pH values. The spectrum at pH 10.08 can be explained by the presence of protonated and deprotonated doxorubicin species.

Calix[n]arene-based coordination networks are an emerging class of materials with intriguing properties resulted from the presence of the cavity-like structure of the macrocycle and metallic nodes. In this work, four novel luminescent materials based on calix[4]arene-carboxylate and lanthanides (Eu3+ and Tb3+) were prepared by two synthetic approaches, solvothermal (CDA-Eu-ST) and slow diffusion (CDA-Eu-RT, CDA-Tb-RT, CTA-Tb-complex) methods. The coordination networks were characterized by PXRD, FTIR, SEM and solid-state photoluminescence, and the results indicated the formation of two different CDA-Eu-structures governed by the synthesis parameters. Single-crystal X-ray diffraction of CTA-Tb-complex revealed the formation of a new dinuclear complex of calix[4]arene-tetracarboxylate containing Na+ and Tb3+ coordinated within the lower rim of the molecule. Preliminary studies showed that CDA-Eu-RT was capable of selectively sensing Fe3+ ions in water via quenching the luminescence, demonstrating the possibility of using calix[4]arene-based platforms as efficient luminescent sensors.