ABSTRACT: Heart failure (HF) is characterized by energy deprivation, calcium (Ca2+) handling alterations, and inflammation: effects associated with mitochondrial dysfunction. Cannabidiol previously prevented mitochondrial dysfunction. Thus, it may prevent HF progression. In mice with HF, subcutaneous cannabidiol attenuated cardiac fibrosis, hypertrophy, loss of ejection fraction, and inflammation; isolated cardiomyocytes preserved cell shortening, Ca2+ handling, mitochondrial function and redox balance. Hypertrophied ventricular cardiomyoblasts suggested cannabidiol-mediated effects through peroxisome proliferator-activated gamma receptors. Therefore, cannabidiol in HF limited cardiac hypertrophy and preserved contractile function by sustaining cardiomyocyte and mitochondrial function through redox balance maintenance, supporting cannabidiol role as a cardioprotective therapy in HF. © The Authors. Published by Elsevier.

ABSTRACT: This study investigates the differential cytotoxicity of reduced graphene oxide (RGO) and graphene oxide (GO) particles using an angiotensin II (Ang II)-induced hypertrophy model in H9c2 cells. Herein, GO particles were synthesized from graphite, and subsequent reduction was carried out to obtain RGO particles. To ensure a thorough assessment of particle size, functionalization, and purity, the particles were characterized by using UV–vis absorbance spectroscopy, dynamic light scattering, X-ray photoelectron spectroscopy, FTIR spectroscopy, Raman spectroscopy, and scanning electron microscopy. Comprehensive characterization revealed that the transformation from GO (∼21.6% content of oxygen) to RGO (∼13.3% content of oxygen) results in an enrichment in the proportion of sp2 carbon. Additionally, rat cardiac myoblasts of the H9c2 cell line were subjected to Ang II to induce cellular hypertrophy, leading to cytoskeleton remodeling, increased cardiac myocyte surface area, extracellular matrix alterations, and collagen type 1a upregulation. To evaluate cytotoxicity, H9c2 cells were treated with RGO and GO suspensions at concentrations ranging from 1 to 10,000 μg/mL, and metabolic viability was assessed in both concentration- and time-dependent assays. GO and RGO reduced the viability of H9c2 cells; however, the metabolic viability assays showed that the half-maximal inhibitory concentration (IC50) values for GO and RGO were significantly lower in hypertrophic cardiomyocytes, with GO exhibiting an IC50 of 12.6 ± 10.7 μg/mL and RGO exhibiting an IC50 of 86.3 ± 12.9 μg/mL, compared to control cells (676.0 ± 80.3 μg/mL for GO and 152.9 ± 40.1 μg/mL for RGO). These results demonstrate that under hypertrophic conditions, there is a significant increase of cytotoxicity for GO (50-fold increase) in comparison to RGO (1.7-fold increase). It was demonstrated that GO particles create a pro-oxidative environment that ultimately leads to mechanistic impairments and cell death. Vulnerable populations predisposed to cardiac damage may be at increased risk of experiencing toxicity caused by the use of GO particles in potential bioapplications. © The Authors. Published by ACS.

ABSTRACT: The cannabinoid receptor 1 (CB1) is an essential component of the endocannabinoid system, responsible for regulating various physiological processes such as pain, mood, and appetite. Despite increasing interest in the therapeutic potential of CB1 modulators, the precise mechanisms by which small molecules modulate receptor activity—particularly without fully transitioning between active and inactive states—remain partially understood. In this study, the complexity of CB1–ligand interactions was evaluated for the inactive CB1 state. A comprehensive pipeline, integrating ligand-based similarity search, 2D fingerprint-based reverse virtual screening and molecular dynamics (MD) simulations, identified compounds with core scaffolds commonly found in bioactive natural products, such as stilbenoids and polyphenolic compounds. Arachidin-2 (AR2) and a polyphenolic derivative were subjected to extended MD simulations, revealing their ability to stabilize the inactive CB1 state across key helices. The distinct stability differences observed in the helices HI, HIV, and HVI of the active CB1 state further highlighted ligand-specific conformational dynamics. A comparative analysis with co-crystallized synthetic ligands AM6538 and AM841 demonstrated the distinct binding behaviors of natural and synthetic ligands. AR2 showed more favorable binding to the inactive form (−22.0 kcal/mol) than to the active state. Similarly, the polyphenolic compound exhibited a greater binding difference (∼6 kcal/mol) between the inactive and active states. Notably, AM6538 and AM841 demonstrated the strongest binding (∼30 kcal/mol) to the inactive and active state, respectively. Key residues stabilizing the identified compounds in CB1-inactive state included PHE102, GLY166, PHE170, VAL196, LEU359, SER383, and CIS386. These findings underscore the utility of computational methods in the discovery and development of novel CB1 modulators for potential biomedical applications. © 2024-2025 Elsevier B.V.

ABSTRACT: Spinel-type compounds exhibit versatile structural and functional properties, which stems from the unique cation distribution that spans a spectrum from partial to total cell inversion degrees. In this study, we investigated the preparation of MnCo₂O₄ particles synthesized via a modified sol-gel method. The synthesized particles were thoroughly characterized using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and Rietveld refinements to assess their microstructural properties. The impact of different annealing temperatures (1000, 1100, and 1200 ◦C) and durations (1 and 8 h) on the crystal evolution of the synthesized particles was systematically investigated to assess the structural adaptability of the MnCo₂O₄ spinel under these synthesis conditions. The degree of inversion and oxygen positional parameters within the crystalline systems were quantified using the Bertaut method to obtain the specific arrangement of manganese and cobalt ions for inversion degrees from approximately 0.85 (random) to 1.00 (inversion) with the presence of a secondary phase of Co3O4 (20 wt%). The lattice parameter was determined from Rietveld analysis to be 8.2720 and 8.2927 Å for the normal and inverted spinel, respectively. Finally, the I(220)/I(400) and I(400)/I(422) intensity ratios were identified as reliable indicators of inversion degree, with these intensities ratios significantly influenced by the oxygen positional parameter. © Elsevier 2024.

ABSTRACT: Spinel-type compounds are known for their substantial chemical and structural variability, which arises from the unique cation distribution characterized by a range of partial to total cell inversion degrees. In this study, we first assessed the preparation of ZnFe2O4 particles synthesized using a hydrothermal method and subsequent calcination. The synthesized particles were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction, Rietveld refinements, and Williamson-Hall fittings to evaluate the microstructural features. The degree of inversion of the crystalline systems was quantified using the Bertaut method. The effect of post-synthesis heat treatments on the crystal evolution of the synthesized particles was investigated at different temperatures (400, 600, and 800 °C) and durations (1, 4, and 8 h). The compressive crystal evolution of the particles with various degrees of cell inversion was observed and correlated with the different heat treatment conditions. The evaluated degrees of inversion were 0.59 (inversion), 0.34 (random), and 0.26 (standard). The cation distribution suggests that the spinel structure can be inverted at the nanoscale regime. The proposed method of particle preparation allows for tuning both the cation distribution and the crystal evolution of the particles from inverted to standard. © Elsevier 2023.

ABSTRACT: Spinel-type compounds are known for their substantial chemical and structural variability, which arises from the unique cation distribution characterized by a range of partial to total cell inversion degrees. In this study, we first assessed the preparation of ZnFe2O4 particles synthesized using a hydrothermal method and subsequent calcination. The synthesized particles were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction, Rietveld refinements, and Williamson-Hall fittings to evaluate the microstructural features. The degree of inversion of the crystalline systems was quantified using the Bertaut method. The effect of post-synthesis heat treatments on the crystal evolution of the synthesized particles was investigated at different temperatures (400, 600, and 800 °C) and durations (1, 4, and 8 h). The compressive crystal evolution of the particles with various degrees of cell inversion was observed and correlated with the different heat treatment conditions. The evaluated degrees of inversion were 0.59 (inversion), 0.34 (random), and 0.26 (standard). The cation distribution suggests that the spinel structure can be inverted at the nanoscale regime. The proposed method of particle preparation allows for tuning both the cation distribution and the crystal evolution of the particles from inverted to standard. © Elsevier 2023.

ABSTRACT: Green synthesis of metallic nanoparticles using microalgae exposed to high CO2 atmospheres has not been studied in detail; this is of relevance in biological CO2 mitigation systems where considerable biomass is produced. In this study, we further characterized the potential of an environmental isolate Desmodesmus abundans acclimated to low and high CO2 atmospheres [low carbon acclimation (LCA) and high carbon acclimation (HCA) strains, respectively] as a platform for silver nanoparticle (AgNP) synthesis. As previously characterized, cell pellets at pH 11 were selected from the biological components tested of the different microalgae, which included the culture collection strain Spirulina platensis. AgNP characterization showed superior performance of strain HCA components as preserving the supernatant resulted in synthesis in all pH conditions. Size distribution analysis evidenced strain HCA cell pellet platform (pH 11) as the most homogeneous AgNP population (14.9 ± 6.4 nm diameter, −32.7 ± 5.3 mV) followed by S. platensis (18.3 ± 7.5 nm, −33.9 ± 2.4 mV). In contrast, strain LCA presented a broader population where the size was above 100 nm (127.8 ± 14.8 nm, −26.7 ± 2.4 mV). Fourier-transform infrared and Raman spectroscopies showed that the reducing power of microalgae might be attributed to functional groups in the cell pellet from proteins, carbohydrates, and fatty acids and, in the supernatant, from amino acids, monosaccharides, disaccharides, and polysaccharides. Microalgae AgNPs exhibited similar antimicrobial properties in the agar diffusion test against Escherichia coli. However, they were not effective against Gram (+) Lactobacillus plantarum. It is suggested that a high CO2 atmosphere potentiates components in the D. abundans strain HCA for nanotechnology applications. © 2023

ABSTRACT: The widespread use of titanium dioxide (TiO2) has raised concerns about potential health risks associated with its cytotoxicity in the cardiovascular system. To evaluate the cytotoxicity of TiO2 particles, the H9c2 rat cardiomyoblasts were used as a biological model, and their toxicological susceptibility to TiO2-anatase and TiO2-rutile particles was studied in vitro. The study examined dose and time exposure responses. The cell viability was evaluated based on metabolic inhibition and membrane integrity loss. The results revealed that both TiO2-anatase and TiO2-rutile particles induced similar levels of cytotoxicity at the inhibition concentrations IC25 (1.4–4.4 μg/cm2) and IC50 (7.2–9.3 μg/cm2). However, at more significant concentrations, TiO2-rutile appeared to be more cytotoxic than TiO2-anatase at 24 h. The study found that the TiO2 particles induced apoptosis events, but necrosis was not observed at any of the concentrations of particles used. The study considered the effects of microstructural properties, crystalline phase, and particle size in determining the capability of TiO2 particles to induce cytotoxicity in H9c2 cardiomyoblasts. The microstress in TiO2 particles was assessed using powder X-ray diffraction through Williamson–Hall and Warren–Averbach analysis. The analysis estimated the apparent crystallite domain and microstrain of TiO2-anatase to be 29 nm (ε = 1.03%) and TiO2-rutile to be 21 nm (ε = 0.53%), respectively. Raman spectroscopy, N2 adsorption isotherms, and dynamic light scattering were used to identify the presence of pure crystalline phases (>99.9%), comparative surface areas (10 m2/g), and ζ-potential values (−24 mV). The difference in the properties of TiO2 particles made it difficult to attribute the cytotoxicity solely to one variable. © 2023

ABSTRACT: The present study provides a comprehensive assessment of the synthesis, crystal evolution, and degree of inversion of the spinel CoCr2O4 (i.e., cochromite) by a modified sol–gel method using propylene oxide and ultrasonication. Ultrasonic assistance promotes the dissociation and dispersibility of Co2+ and Cr3+ precursors, contributing to the hydrolysis reaction to form hydrated ions. Propylene oxide serves as a proton scavenger to provide the conditions needed for homogeneous gelation. Heat treatments at different temperatures (400, 550, and 700 °C) for different durations (1, 4, and 8 h) have been applied to follow the crystal evolution and the inversion of the spinel system. The formation of CoCr2O4 particles was observed at approximately 400 °C. An increase in calcination temperature induced particle size growth (from 12 to 42 nm) and sintering effects. A significant decrease in the specific surface area (from 144 to 33 m2 g−1) was observed with changes in the lattice parameter (8.304–8.334 Å). Raman, XPS, XRD, and Rietveld analyses indicated the presence of a pure cochromite phase. The Bertaut method has been applied to monitor the inversion process of CoCr2O4 during post-synthesis heat treatment. The spinel conformation became a regular type beyond 700 °C, whereas a fully inverted structure was obtained at lower temperatures. The modified sol–gel method may be convenient for large-scale production to synthesize other spinel-type compounds. © 2023 Elsevier

ABSTRACT: Conformational changes and stability of interacting double-stranded DNA chains under high hydrostatic pressure in biological systems are striking topics of importance to study several biomolecular phenomena. For example, to unravel the physiological conditions at which life might occur and to ensure the right functionality of the biochemical processes into the cell under extreme thermodynamic conditions. Furthermore, such processes could shed light on the physicochemical properties of the DNA under high confinement and how, through different mechanisms, a virus releases its genome in order to infect a cell and, therefore, to promote the process of viral replication. To achieve a few steps toward this direction, we propose an all-atomistic molecular dynamics approach in the NPT isothermal-isobaric ensemble to account for how the interplay of DNA—DNA interaction, hydrogen bonding, and the hydrostatic pressure modifies both the DNA conformational degrees of freedom and the spatial organization of the DNA chains in the available volume. We consider two interacting double-stranded DNA chains immersed in an explicit aqueous solution, i.e., water and ions. Our preliminary results highlight the role of hydrogen bonding and electrostatic interactions between DNA strands to avoid denaturation and, therefore, to provide mechanical stability for the DNA molecules. However, the structural evolution, whose kinetics depends on the relaxation of the stresses induced by the pressure, indicates that almost in all pressure conditions, the equilibrium configuration corresponds to an alignment of the two double-stranded DNA molecules along their main axis of symmetry; the rearrangement between the two approaching DNA dodecamers does not always correspond to complementary base pairs and becomes a function of the thermodynamic conditions. © 2023 by the Authors (CC BY License)

ABSTRACT: In addition to playing a central role in the mitochondria as the main producer of ATP, FOF1-ATP synthase performs diverse key regulatory functions in the cell membrane. Its malfunction has been linked to a growing number of human diseases, including hypertension, atherosclerosis, cancer, and some neurodegenerative, autoimmune, and aging diseases. Furthermore, inhibition of this enzyme jeopardizes the survival of several bacterial pathogens of public health concern. Therefore, FOF1-ATP synthase has emerged as a novel drug target both to treat human diseases and to combat antibiotic resistance. In this work, we carried out a computational characterization of the binding sites of the fungal antibiotic aurovertin in the bovine F1 subcomplex, which shares a large identity with the human enzyme. Molecular dynamics simulations showed that although the binding sites can be described as preformed, the inhibitor hinders inter-subunit communications and exerts long-range effects on the dynamics of the catalytic site residues. End-point binding free energy calculations revealed hot spot residues for aurovertin recognition. These residues were also relevant to stabilize solvent sites determined from mixed-solvent molecular dynamics, which mimic the interaction between aurovertin and the enzyme, and could be used as pharmacophore constraints in virtual screening campaigns. To explore the possibility of finding species-specific inhibitors targeting the aurovertin binding site, we performed free energy calculations for two bacterial enzymes with experimentally solved 3D structures. Finally, an analysis of bacterial sequences was carried out to determine conservation of the aurovertin binding site. Taken together, our results constitute a first step in paving the way for structure-based development of new allosteric drugs targeting FOF1-ATP synthase sites of exogenous inhibitors. © 2022 by the Authors (CC BY License)

ABSTRACT: Scanning tunneling microscopy (STM) is a technique that can be used to directly observe individual biomolecules at near-molecular scale. Within this framework, STM is of crucial significance because of its role in the structural analysis, the understanding the imaging formation, and the development of relative techniques. Four decades after its invention, it is pertinent to ask how much of the early dream has come true. In this study, we aim to overview different analyses for DNA, lipids, proteins, and carbohydrates. The relevance of STM imaging is exhibited as an opportunity to assist measurements and biomolecular identification in nanobiotechnology, nanomedicine, biosensing, and other cutting-edge applications. We believe STM research is still an entire science research ecosystem for joining several areas of expertise towards a goal settlement that has been elusive for many years. 

© 2022 by the Authors. Licensee MDPI, Basel, Switzerland

ABSTRACT: Photosensitive supramolecular systems have garnered attention due to their potential to catalyze highly specific tasks through structural changes triggered by a light stimulus. The tunability of their chemical structure and charge transfer properties provides opportunities for designing and developing smart materials for multidisciplinary applications. This review focuses on the approaches reported in the literature for tailoring properties of the photosensitive supramolecular systems, including MOFs, MOPs, and HOFs. We discuss relevant aspects regarding their chemical structure, action mechanisms, design principles, applications, and future perspectives.

© 2022 by the Authors. Licensee MDPI, Basel, Switzerland

ABSTRACT: The research of carbon nanotubes (CNTs) has contributed to basic science and is playing leading roles in potential applications, including nanomedicine. In particular, CNTs have been proposed as nanocarriers for cancer therapeutics. This study reviews the advantages and potential challenges of using CNTs in chemotherapy drug-delivery formulations. We mainly focus on tumor-targeted systems prepared with hyaluronic acid and folic acid because of their biocompatibility, low cost, ease of conjugation to targeting agents, and specificity for pathologic cells. The relevance of these CNTs-based tumor-targeted drug-delivery systems is discussed for cisplatin, carboplatin, doxorubicin, gemcitabine, salinomycin, chlorin e6, and paclitaxel. An extensive and diversified list of methodologies for preparing these drug-delivery systems provides a rationale for definite protocols to attain comparability between conjugates prepared from different formulations. Hence, the scope of various CNTs-based tumor-targeted drug-delivery systems was reviewed from a perspective relating to the opportunities of using CNTs in chemotherapeutics and the challenges associated with developing formulations for human use. 

© 2022 American Chemical Society 

ABSTRACT: The increasing demand for single‐use plastic‐based products worldwide has generated immense waste during the last decade. This review aims to summarize the current developments of surface‐enhanced Raman spectroscopy (SERS) for detecting micro‐ and nanoplastics in a variety of samples and environments. Despite the SERS technique being very recent for this purpose, its robustness has already been discussed in a few analyses focused on well‐known pollutants such as phthalates, plasticizers, and xenobiotic contaminants from commercially available water bottles. Here, the latest advances, obstacles, and perspectives are reviewed using SERS detection as a robust alternative for analyzing complex samples containing nanoplastic particles present in daily consumer products such as wine and vegetables. Moreover, this paper describes different SERS substrates developed to overcome the limitations for identifying polymer particles at low concentrations. Factors contributing to the sensitivity of SERS substrates are discussed to show the advantages and limitations of this technique. The broader role of SERS as a tool in environmental research is currently explored from polluted air and aquatic environments, which can be relevant for other fields, such as clinical monitoring and nanotoxicology. 

© 2022 Wiley-VCH GmbH 

ABSTRACT: A numerical model that describes the transport of mobile ionic species in metal–insulator–semiconductor (MIS) and photovoltaic (PV) devices subject to temperature and voltage stress is presented. The finite element method (FEM) is used to solve the Nernst–Planck equation while imposing Poisson's equation self-consistently as a restriction for the electrostatic potential. This allows the contribution of the ionic species to the potential to be taken into account. Using a variational formulation eases the implementation of diverse boundary conditions, including the incorporation of segregation kinetics at the device interfaces. Segregation across the dielectric–semiconductor interface is relevant to modeling the electronic device degradation in systems where contamination reaches the semiconductor. The model in closed systems with no-flux boundary conditions is validated first. In the limiting case of low contamination levels with respect to the gate bias, the FEM solution matches analytically derived approximations. Then, the implementation is broadened to include an open boundary at the dielectric–semiconductor interface to account for leakage of ions. The predicted time dependence of the flatband voltage in Na-contaminated MIS test structures agrees well with measurements. The model successfully captures the role of long-range ion transport at concentrations of relevance to electronic and PV device instability and neuromorphic computing. 

© 2021 Wiley-VCH GmbH 

ABSTRACT: Cancer is a major global public health problem and conventional chemotherapy has several adverse effects and deficiencies. As a valuable option for chemotherapy, nanomedicine requires novel agents to increase the effects of antineoplastic drugs in multiple cancer models. Since its discovery, carbon nanotubes (CNTs) are intensively investigated for their use as carriers in drug delivery applications. This study shows the development of a nanovector generated with commercial carbon nanotubes (cCNTs) that were oxidized (oxCNTs) and chemically functionalized with hyaluronic acid (HA) and loaded with carboplatin (CPT). The nanovector, oxCNTs–HA–CPT, was used as a treatment against HeLa and MDA–MB-231 human tumor cell lines. The potential antineoplastic impact of the fabricated nanovector was evaluated in human cervical adenocarcinoma (HeLa) and mammary adenocarcinoma (MDA-MB-231). The oxCNTs–HA–CPT nanovector demonstrate to have a specific antitumor effect in vitro. The functionalization with HA allows that nanovector bio–directed towards tumor cells, while the toxicity effect is attributed mainly to CPT in a dose-dependent manner. 

© 2021 by the authors. Licensee MDPI, Basel, Switzerland.

ABSTRACT: Graphene oxide powder and graphene oxide paper were covalently functionalized with the 4′-aminobenzo-15-crown-5 (AB15C5) and 4′-aminobenzo-18-crown-6 (AB18C6) ethers by a solvent-free gas-phase treatment. Then, we attempted the complexation with potassium and sodium cations. A comparative characterization in the functionalized graphene oxide structures was carried out using Fourier-transform infrared (FTIR), Raman and X-ray photoelectron spectroscopy (XPS), thermogravimetric and differential thermal analysis (TGA and DTA, respectively), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The wettability of graphene oxide paper (GOP) samples was analyzed by measuring the contact angle. The degree of covalent functionalization in GO powder with aminobenzo-crown ethers was estimated at 27% (AB15C5) and 19% (AB18C6). The amount of organics attached to GOP samples was approximately 7%. After the interaction with potassium and sodium cations, the functionalized GOP samples showed an increase in the contact angle, followed by a decrease in surface free energy. The complexation with alkali metal cations suggests an uptake of about 3%. However, the cation selectivity for alkali metal ions was dependent on the ions' radius. Surface free energy measurements suggest that complexation with potassium effectively takes place when using AB18C6. 

© 2021 Elsevier B.V.

ABSTRACT: Polycrystalline structures, such as nanoparticles and thin-films, commonly broaden X-ray line profiles due to the presence of dislocation substructures. In this study, the microstructures of gold nanoparticles (AuNPs) and gold thin-films (AuTFs) were analyzed through X-ray line profile analysis according to a series of integral breadth methods. Our estimations suggest, in all cases, a larger crystallite size for AuTFs of about 8.0 ± 2.0 nm. However, our calculations yielded a very low dislocation density of the order 1013 (m−2) for AuTFs, whereas it is one order higher in AuNPs. The estimated upper limit of strain was calculated as about 0.28 and 0.068 for AuNPs and AuTFs, respectively. With the assumption of the presence of strain, the averaged distances among dislocations are lower in AuNPs (40.8 nm) than AuTFs (163.2 nm). Therefore, it has been suggested that the broadening in AuNPs arises from both small crystallites and microstrain effects, whereas it arises in AuTFs mainly due to size effects. These results allow the identification of reflections with a particular state of strain and outline the presence of anisotropy in the samples. A notorious characteristic is the peak broadening in the (200) and (311) reflections. In particular, the broadening in the plane (200) suggests that the source of the strain is due to dislocations in the a/2<110>{111} primary slip system. Contrast factor calculations indicate that edge-type dislocations contribute to the presence of strain. A qualitative description of the edge/screw characteristics of dislocations is shown using a graphical representation for the displacement field in both edge and screw <110>{111} slip systems. The lattice parameter was extrapolated as about 4.0739 and 4.0746 Å for AuNPs and AuTFs, respectively. 

© 2021 Elsevier B.V.

ABSTRACT: Silica nanoparticles (nanoSiO2) are promising systems that can deliver biologically active compounds to tissues such as the heart in a controllable manner. However, cardiac toxicity induced by nanoSiO2 has been recently related to abnormal calcium handling and energetic failure in cardiomyocytes. Moreover, the precise mechanisms underlying this energetic debacle remain unclear. In order to elucidate these mechanisms, this article explores the ex vivo heart function and mitochondria after exposure to nanoSiO2. Results: The cumulative administration of nanoSiO2 reduced the mechanical performance index of the rat heart with a half-maximal inhibitory concentration (IC50) of 93 μg/mL, affecting the relaxation rate. In isolated mitochondria nanoSiO2 was found to be internalized, inhibiting oxidative phosphorylation and significantly reducing the mitochondrial membrane potential (Δψm). The mitochondrial permeability transition pore (mPTP) was also induced with an increasing dose of nanoSiO2 and partially recovered with, a potent blocker of the mPTP, Cyclosporine A (CsA). The activity of aconitase and thiol oxidation, in the adenine nucleotide translocase, were found to be reduced due to nanoSiO2 exposure, suggesting that nanoSiO2 induces the mPTP via thiol modification and ROS generation. In cardiac cells exposed to nanoSiO2, enhanced viability and reduction of H2O2 were observed after application of a specific mitochondrial antioxidant, MitoTEMPO. Concomitantly, CsA treatment in adult rat cardiac cells reduced the nanoSiO2-triggered cell death and recovered ATP production (from 32.4 to 65.4%). Additionally, we performed evaluation of the mitochondrial effect of nanoSiO2 in human cardiomyocytes. We observed a 40% inhibition of maximal oxygen consumption rate in mitochondria at 500 μg/mL. Under this condition we identified a remarkable diminution in the spare respiratory capacity. This data indicates that a reduction in the amount of extra ATP that can be produced by mitochondria during a sudden increase in energy demand. In human cardiomyocytes, increased LDH release and necrosis were found at increased doses of nanoSiO2, reaching 85 and 48%, respectively. Such deleterious effects were partially prevented by the application of CsA. Therefore, exposure to nanoSiO2 affects cardiac function via mitochondrial dysfunction through the opening of the mPTP. Conclusion: The aforementioned effects can be partially avoided reducing ROS or retarding the opening of the mPTP. These novel strategies which resulted in cardioprotection could be considered as potential therapies to decrease the side effects of nanoSiO2 exposure. 

© 2020 The Author(s)

ABSTRACT: Gold nanoparticles (AuNPs) are considered valuable nanomaterials for the design of radiolabeled nanoprobes for single-photon emission computed tomography (SPECT) imaging. Radiolabeled and functionalized AuNPs could improve lymphatic mapping by enhancing the radioactive signaling of individual particles in the sentinel node. In this study, an alternative method for functionalizing commercial AuNps with mannose is described. The chemical derivatization and biofunctionalization of AuNPs were performed with lipoic acid and mannose, respectively. Several levels of mannose were tested; the thiolate hydrazinonicotinamide-glycine-glycine-cysteine (HYNIC) molecule was also used for 99mTc radiolabeling. Physicochemical characterization of this system includes U-V spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy. The most stable nanoprobe, in terms of the aggregation, radiolabeling efficiency, and purity, was tested in a sentinel lymph node model in a rat by microSPECT/computed tomography (CT) imaging. The SPECT images revealed that 99mTc-radiolabeled AuNPs functionalized with mannose can track and accumulate in lymph nodes in a similar way to the commercial 99mTc-Sulfur colloid, commonly used in clinical practice for sentinel lymph node detection. These promising results support the idea that 99mTc-AuNPs-mannose could be used as a SPECT contrast agent for lymphatic mapping. 

© 2020 by the authors. Licensee MDPI, Basel, Switzerland.

ABSTRACT:  The noncovalent bonding between nucleobases (NBs) and Stone–Wales (SW) defect-containing closed-end single-walled carbon nanotubes (SWNTs) was theoretically studied in the framework of density function theory using a dispersion-corrected functional PBE-G06/DNP. The models employed in this study were armchair nanotube (ANT) (5,5) and zigzag nanotube (ZNT) (10,0), which incorporated SW defects in different orientations. In one of them, the (7,7) junction is tilted with respect to SWNT axis (ANT-t and ZNT-t), whereas in ANT-p and ZNT-p models the (7,7) junction is parallel and perpendicular to the axis, respectively. The binding energies for uracil, thymine, cytosine, 5-methylcytosine, adenine, and guanine interacting with the defect-containing nanotube models were compared to the values previously obtained with the same calculation technique for the case of defect-free SWNTs, both in the gas phase (vacuum) and in aqueous medium. For most models, the interaction strength tends to be higher for purine than for pyrimidine complexes, with a clear exception of the systems including ZNT-p, both in vacuum and in aqueous medium. As it could be expected, the binding strength in the latter case is lower as compared to that in vacuum, roughly by 2–4 kcal/mol, due to the implicit inclusion of a medium (i.e., water) via the conductor-like screening model model. The closest contacts between NBs and SWNT models, frontier orbital distribution, and highest-occupied molecular orbital–lowest-unoccupied molecular orbital gap energies are analyzed as well. 

© 2019 Wiley Periodicals, Inc.

© 2019 American Chemical Society

BSTRACT: Solid materials that do not present a perfect crystalline structure at long range are called polycrystalline materials. This deviation from a perfect crystallinity is known as the microstructure and determines the properties of materials. The microstructure can be studied by the analysis of X-ray diffraction patterns, which is known as X-ray line profile analysis (XLPA). The peaks in the diffractogram can broaden due to crystallite size, density of dislocations, planar defects, chemical heterogeneities, and surface relaxation. This allows the analysis of the microstructure via XLPA. Here, a review of the methods developed for XLPA analysis is presented. From the classical methods of Williamson-Hall and Warren-Averbach, to their modified versions and modern analysis methods are briefly described, as well as their scope and limitations. The conclusions present the area of opportunity of XLPA in polycrystalline solids today, as well as potential applications in materials science. 

© 2020 Elsevier Ltd

ABSTRACT: Carbon nanotubes (CNTs) have emerged in recent years as a potential option for drug delivery, due to their high functionalization capacity. Biocompatibility and selectivity using tissue-specific biomolecules can optimize the specificity, pharmacokinetics and stability of the drug. In this study, we design, develop and characterize a drug nanovector (oxCNTs-HA-CPT) conjugating oxidated multi-wall carbon nanotubes (oxCNTs) with hyaluronate (HA) and carboplatin (CPT) as a treatment in a lung cancer model in vitro. Subsequently, we exposed TC–1 and NIH/3T3 cell lines to the nanovectors and measured cell uptake, cell viability, and oxidative stress induction. The characterization of oxCNTs-HA-CPT reveals that on their surface, they have HA. On the other hand, oxCNTs-HA-CPT were endocytosed in greater proportion by tumor cells than by fibroblasts, and likewise, the cytotoxic effect was significantly higher in tumor cells. These results show the therapeutic potential that nanovectors possess; however, future studies should be carried out to determine the death pathways involved, as well as their effect on in vivo models.  

© 2019 by the authors. Licensee MDPI, Basel, Switzerland.

ABSTRACT: The growing interest in the use of powder X-ray diffractometry for materials’ characterization has led to the introduction of relevant concepts (e.g. microstructure, strain, anisotropy, texture) to undergraduate teaching in engineering and science. In this concern, the study of polycrystalline materials underlays the use of appropriate software: free, licensed, proprietary, or commercial to assist research on structure determination, structure refinement, and microstructure characterization. Today with the easy access to personal computers, routines for powder diffractometry also becomes feasible to use for non-specialist. Therefore, it would be relevant that students with computing knowledge may decide to improve routines on such three tasks incorporating their own computational approaches. In this study, we show the development of a ready-to-use and open source program written in GNU-Octave (v4.2.1) focused on X-ray diffraction line-profile analysis. The programing language platform was chosen mainly because of two reasons: (1) there is no requirement for commercial licenses, meaning that both programing language and routines can be downloaded online, facilitating collaborative efforts between students, instructors, and developers, and (2) easy re-coding of evaluation strategies is always allowed through fast implementation of modules into the code. The code, IndexCub, features routines for background subtraction, whole profile smoothing, and Kα2 radiation removal, location of diffraction peaks positions, indexing for cubic specimens, multi peak separation of individual peaks, and evaluation of full-width at half-maximum and integral breadth values. Microstructure properties are characterized through the use of integral breadth methods (e.g. Williamson–Hall) and Fourier analysis (e.g. Warren–Averbach), and the anisotropy effects are incorporated introducing calculations of contrast factors. In terms of diffraction domain sizes, size distribution, and the lattice microstrain, the analysis of the microstructure is discussed along with examples for polycrystalline coarse-grained materials (NaCl), epitaxial film (Si), and thin-films (Au) specimens. The code facilitates the understanding of microstructure analysis by using theoretical approaches well established and in state-steady level. 

© 2019 International Center for Diffraction Data

ABSTRACT: The microstructural properties of polycrystalline materials can be indirectly analyzed through X-ray diffraction data. To this, the diffraction-line broadening phenomena is taking into account as a basis to develop theoretical approaches focusing on determinate defects into the crystal structure (e.g., dislocations, stacking and twin faults, lattice distortions, vacancies) as well as their concentrations and distributions. In this study, X-ray Line Profile Analysis (XLPA) from two pure samples of anatase and rutile TiO2 powders were conducted to look at their microstructural characterization using the classical Williamson Hall (WH) and Warren Averbach (WA) methods. WH microstructural analysis indicates that the calculated strain contribution at the upper limit is 1.89% and 1.31% for anatase and rutile, respectively, while the root mean-square of the variations in the strain was determined using the WA method to obtain percentages in about 0.23% and 0.30% for anatase and rutile, respectively. The area-weighted mean column length, , was determine using WA obtaining 42 nm and 91 nm in anatase and rutile phases, respectively. 

© 2019 Elsevier Ltd.

The International Conference on Nanotechnology Tec.Nano 2018 is the first conference organized by Tecnológico de Monterrey to attend notable research in the areas of fundamental and applied nanotechnology by lending a special focus on the topics of Advanced and Smart Materials, Nanodevices, Nanomaterials Processing and Characterization, Nanophotonics, Nanobiotechnology and Nanomedicine, and Lab-on-a-chip. The conference was held in Monterrey, Mexico, on November 28-30, and scheduled an agenda organized by plenary lectures, oral and poster presentations, forums, workshops, and nanotech company exhibitions. The event was honored to join prestigious personalities as our invited speakers. The plenary sessions were conducted by Prof. H. Kumar Wickramasinghe (University of California, USA, and The Federico Baur Endowed Chair Professor in Tecnológico de Monterrey, México), Prof. Pierre Berini (University of Ottawa, Canada); Prof. Jeffrey W. Stansbury (University of Colorado, USA); Dr. Elvin Blanco (The Houston Methodist Research Institute, USA); and Dr. Joel Voldman (Massachusetts Institute of Technology, USA). A specialized committee supported by a chair directed the participation of 110 abstracts, which were received for both oral and poster presentations. The selected peer-reviewed papers presented at Tec.Nano 2018 are now published in this special issue. After a modest beginning of this event, I acknowledge the efforts of many people whose talents were required to make it a reality. I wish to express my sincere gratitude to the Organizing Committee: Laura Romero, Doraelia Hernández, José González-Valdez and Sergio Martínez-Chapa. Finally, I am especially grateful to Stewart Bland for the given opportunity to show the Tec.Nano initiative into a special issue of this prestigious journal. I hope this conference will rapidly become one of the annual appointments that can bring a broader participation of researchers in subsequent editions.

Dr. Flavio F. Contreras-Torres

Guest Editor

© 2019 Elsevier Ltd.

40. D. Cavazos-Cavazos, F.F. Contreras-Torres*. “Determination of contrast factors for cubic slip-systems and their application in the microstructural characterization of binary Fm3m materials”. Journal of Physics and Chemistry of Solids 2017, 110, 36-42.

39. N. Ornelas-Soto, R. Rubio-Govea, C.E. Guerrero-Beltrán, E. Vázquez-Garza, J. Bernal-Ramírez, A. García-García, Y. Oropeza-Almazán, G. García-Rivas, F.F. Contreras-Torres*. “Enhancing internalization of silica particles in myocardial cells through surface modification”. Materials Science and Engineering C 2017, 79, 831-840.

38. F.F. Contreras-Torres*, A. Rodríguez-Galván, C.E. Guerrero-Beltrán, E. Martinez-Lorán, E. Vázquez-Garza, N. Ornelas-Soto, G. García-García. “Differential citotoxicity and internalization of graphene family nanomaterials in myocardial cells”. Materials Science and Engineering C. 2017, 73, 633-642.

37. I. Aguilar-Hernández, N.K. Afseth, T. López-Luke, F.F. Contreras-Torres, J.P. Wold, N. Ornelas-Soto. “Surface enhanced Raman spectroscopy of phenolic antioxidants: A systematic evaluation of ferulic acid, p-coumaric acid, caffeic acid and sinapic acid”. Vib. Spectrosc. 2017, 89, 113-122.

36. A. Rodríguez-Galván, E. Martínez-Lorán, J. Naveja, N. Ornelas-Soto, V.A. Basiuk, F.F. Contreras-Torres*. “In-situ Metallization of Thermally-Treated Tobacco Mosaic Virus using Silver Nanoparticles”. Journal of Nanoscience and Nanotechnology 2017, 17, 4740-4747.

35. M. Rodríguez-Delgado, N. Soto-Ornelas, E. Martínez-Lorán, C. Hernández-Luna, A. García-García, F.F. Contreras-Torres*. “Enhanced enzymatic activity of laccase (from Pycnoporus sanguineus CS43) immobilized on sputtered nanostructured gold thin films”. J. Nanosci. Nanotech. 2017, 17(2), 939-946.

34. O.E. Ochoa-Olmos, J.A. León-Domínguez, F.F. Contreras-Torres, S. Sanchez-Nieto, E.V. Basiuk, T.D. Dinkova. “Transformation of plant cell suspension cultures with amine-fuctionalized multi-walled carbon nanotubes”. J. Nanosci. Nanotech. 2016, 16(7), 7461-7471.

33. F. De Colle, A.C. Raga, F.F. Contreras-Torres, J.C.Toledo-Roy. “A Stellar Wind Origin for the G2 Cloud: Three-Dimensional Numerical Calculations”. Astrophys. J. Lett. 2014, 789, L33 (6pp).

32. Z. Ji, F.F. Contreras-Torres*, A.F. Jalbout, A. Ramírez-Treviño. “Surface Diffusion and Coverage Effect of Li Atom on Graphene as Studied by Several Density Functional Theory Methods”. App. Surf. Sci. 2013, 285 (Part B), 846-852.

31. E.V. Basiuk, A. Santamaría-Bonfil, V. Meza-Laguna, T. Yu. Gromovoy, E. Alvares-Zauco, F.F. Contreras-Torres, J. Rizo, G. Zavala, V.A. Basiuk. “Solvent-Free Covalent Functionalization of Nanodiamond with Amines”. App. Surf. Sci. 2013, 275, 324-334.

30. A. Rodríguez-Galván, F.F. Contreras-Torres*, E.V. Basiuk, A. Heredia, V.A. Basiuk. “Deposition of Silver Nanoparticles onto Human Serum Albumin-Functionalised Multi-Walled Carbon Nanotubes”. Can. J. Chem. Eng. 2013, 91(2), 264-270.

29. E.V. Basiuk, V.A. Basiuk, V. Meza-Laguna, F.F. Contreras-Torres, M. Martínez, A. Rojas-Aguilar, M. Salerno, G. Zavala, A. Falqui, R. Brescia. “Solvent-Free Covalent Functionalization of Multi-Walled Carbon Nanotubes and Nanodiamond with Diamines: Looking for Cross-Linking Effects”. App. Surf. Sci. 2012, 259, 465-476.

28. F.F. Contreras-Torres*, E.V. Basiuk, V.A. Basiuk, V. Meza-Laguna, and T. Yu. Gromovoy. “Nanostructured Derivatives of Diamine-Fullerenes: Computational Density Functional Theory Study and Experimental Evidence for their Formation via Gas-Phase Functionalization”. J. Phys. Chem. A 2012, 116(6), 1663-1676.

27. E.V. Basiuk (Golovataya-Dzhymbeeva), O. Ochoa-Olmos, F.F. Contreras-Torres, V. Meza-Laguna, E. Alvarez-Zauco, I. Puente-Lee, V. A. Basiuk. “Green” Functionalization of Pristine Multi-Walled Carbon Nanotubes with Long-Chain Aliphatic Amines”. J. Nanosci. Nanotech. 2011, 11(6), 5546-5554.

26. A. Rodríguez-Galván, F.F. Contreras-Torres, E.V. Basiuk, E. Álvarez-Zauco, A. Heredia, and V. A. Basiuk. “Aggregation of Human Serum Albumin on Graphite and Single-Walled Carbon Nanotubes as Studied by Scanning Probe Microscopies”. J. Nanosci. Nanotech. 2011, 11(6), 5491-5498.

25. F.F. Contreras-Torres* and E. Martínez-Lorán. “DNA Insertion in and Wrapping around Carbon Nanotubes”. WIREs: Comput. Molec. Sci.  2011, 1(6), 902-919.

24. F.F. Contreras-Torres*, E.V. Basiuk, A. Rodríguez-Galván. “Atomic Force Microscopy of Extraterrestrial Samples” J. Adv. Microsc. Research 2010, 5 (3), 159-176.

23. F.F. Contreras-Torres*, V.A. Basiuk, E.V. Basiuk. “Interaction between NO2 and an Elongated Fullerene C60” J. Comput. Theor. Nanosci. 2010, 7 (2), 408-413.

22. F.F. Contreras-Torres*, O.E. Ochoa-Olmos, E.V. Basiuk. “Amine-Functionalized Multi-Walled Carbon Nanotubes: An Atomic Force Microscopy Study” J. Scann. Probe. Microsc. 2009, 4 (2), 100-106.

21. C.M. Chang, A.F. Jalbout, and F.F. Contreras-Torres. “Computational Notes on the Thermostatistics of the Most Stable Ionic Au32 Isomers” J. Comput. Theor. Nanoscience. 2009, 6 (7), 1491-1493.

20. F.F. Contreras-Torres* and J. Flores-Mijangos. “Vibrational Analysis and DFT Calculations of Neutral and Ionic Au32 Clusters” J. Comput. Theor. Nanosci. 2009, 6 (7), 1717-1721.

19. V.A. Basiuk, F.F. Contreras-Torres, M. Bassiouk, and E.V. Basiuk. “Interactions of Porphyris with Low-Dimensional Carbon Materials” J. Comput. Theor. Nanosci. 2009, 6 (7), 1383-1411.

18. A.F. Jalbout, F.F. Contreras-Torres, A.K. Roy, and A. de Leon. “Monte Carlo Simulation on the RKKY Interaction of Co-Doped ZnS and ZnSe Nano-Films” J. Comput. Theor. Nanosci. 2009, 6 (1), 148-152.

17. F.F. Contreras-Torres*, O. Amelines-Sarria, A.F. Jalbout, E.V. Basiuk, and V.A. Basiuk. “Interactions between Cation-encapsulated Single-Walled Carbon Nanotubes M+@SWNT (M+ = H, Li, Na) and Nucleophiles” Comput. Mater. Sci. 2008, 44 (2), 240-246.

16. F.F. Contreras-Torres*, V.A. Basiuk, and E.V. Basiuk. “Regioselectvity in Azahydro[60]fullerene Derivatives: Application of General-Purpose Reactivity Indicators.” J. Phys. Chem. A 2008, 112 (35), 8154 – 8163.

15. A.F. Jalbout, F. F. Contreras-Torres, and A. de Leon. “Formation of Simple Organic Molecules in the Interstellar Medium” Int. J. Quantum Chem. 2008, 108 (3), 598–606.

14. A.F. Jalbout, F. F. Contreras-Torres, and R. del Castillo. “Solvatation of Excess Electrons Trapped in Charge Pockets on Hydrated Molecular Surfaces” Int. J. Quantum Chem. 2008, 108 (3), 567–575.

13. F.F. Contreras-Torres, A.F. Jalbout, O.F. Amelines, and V.A. Basiuk. “Interaction of Cation-Encapsulated Single-Walled Carbon Nanotubes with Small Polar Molecules” J. Phys. Chem. C 2008, 112 (7), 2736–2742.

12. A.F. Jalbout, F. F. Contreras-Torres, and L. Adamowicz. “The Hydroxyaceatone (CH3COCH2(OH)) Torsional Potential and Isomerization: A Theoretical Study” Int. J. Quantum Chem. 2008, 108(2), 279–288.

11. A,F. Jalbout, F. F. Contreras-Torres, L.A. Pérez, and I.L. Garzón. “Low Symmetry Structures of Au32Z (Z = +1, 0, –1) Clusters” J. Phys. Chem. A 2008, 112 (3), 353–357.

10. A.F. Jalbout, Z. Romanowski, F. Contrerras-Torres, and A. de Leon. “Stabilization of Excess Electrons in Molecular Charge Pockets on Nano-Surfaces” J. Comput. Theor. Nanosci. 2008, 5 (7), 1263–1268.

09. F.F. Contreras-Torres, A.F. Jalbout, O.F. Amelines, and V.A. Basiuk. “Theoretical Modeling of Fullerene-Porphyrin Interaction: Computational Implications” J. Comput. Theor. Nanosci. 2008, 5 (7), 1367–1371.

08. A.F. Jalbout, F. F. Contreras-Torres, A.J. Hammed, B. Trzaskowski and V.A. Basiuk. “Structure and Properties of a Series of ArylSelenium[60]Fulleropyrrolidine Derivatives” J. Comput. Theor. Nanosci. 2008, 5 (4), 554–562.

07. F.F. Contreras-Torres, A. Arzate-Jacinto, and V.A. Basiuk. “Direct Esterification of Oxidized Defects in Single-Walled Carbon Nanotubes: A Comparison of Several ONIOM Computation Schemes”. J. Comput. Theor. Nanosci. 2008, 5(1), 93–101.

06. A.F. Jalbout, F. F. Contreras-Torres, G.M. Lobo, and J.E. Charris. “Structure of Methyl 1-oxo-3,5-diphenylcyclohexe-6-carboxylate” Molbank 2007, M558.

05. A.F. Jalbout, F.F. Contreras-Torres, G.M. Lobo, and J.E. Charris. “Structure of Methyl (1S, 6S) 6-(4-chlorophenyl)-4-(4-methylphenyl)cyclohex-3-en-2-one-1-carboxylate” Molbank 2007, M559.

04. A.F. Jalbout, Md A.H. Shipar, and F.F. Contreras-Torres. “Density Functional Computational Stuides on the Intermediate Stage of Ribose and Glycine Maillard Reaction: Formation of Deoxyosones in Aqueous Solution” Food Chem. 2007, 105 (4), 1342–1348.

03. F.F. Contreras-Torres and V.A. Basiuk. “ONIOM Studies of Esterification at Oxidized Carbon Nanotube Tips” J. Phys. Conf. Series 2007, 61 (1), 85–89.

02. F.F. Contreras-Torres and V.A. Basiuk. “Imidazo[1,2-a]pyrazine-3,6-diones Derived from α-Amino Acids: A Theoretical Mechanistic Study of their Formation via Pyrolysis and Silica-Catalyzed Process” J. Phys. Chem. A 2006, 110 (23), 7431–7440.

01. F.F. Contreras-Torres and V.A. Basiuk. “Theoretical Prediction of Gas-Phase Infrared Spectra of Imidazo[1,2-a]pyrazinediones and Imidazo[1,2-a]imidazo[1,2-d]pyrazinediones Derived from Glycine” Spectrochim. Acta A 2005, 61 (11-12), 2560–2575.