Mechanistic insights into the antitumoral potential and in vivo antiproliferative efficacy of a silver-based core@shell nanosystem.

This study delves into the biomolecular mechanisms underlying the antitumoral efficacy of a hybrid nanosystem, comprised of a silver core@shell (Ag@MSNs) functionalized with transferrin (Tf). Employing a SILAC proteomics strategy, we identified over 150 de-regulated proteins following exposure to the nanosystem. These proteins play pivotal roles in diverse cellular processes, including mitochondrial fission, calcium homeostasis, endoplasmic reticulum (ER) stress, oxidative stress response, migration, invasion, protein synthesis, RNA maturation, chemoresistance, and cellular proliferation. Rigorous validation of key findings substantiates that the nanosystem elicits its antitumoral effects by activating mitochondrial fission, leading to disruptions in calcium homeostasis, as corroborated by RT-qPCR and flow cytometry analyses. Additionally, induction of ER stress was validated through western blotting of ER stress markers. The cytotoxic action of the nanosystem was further affirmed through the generation of cytosolic and mitochondrial reactive oxygen species (ROS). Finally, in vivo experiments using a chicken embryo model not only confirmed the antitumoral capacity of the nanosystem, but also demonstrated its efficacy in reducing cellular proliferation. These comprehensive findings endorse the potential of the designed Ag@MSNs-Tf nanosystem as a groundbreaking chemotherapeutic agent, shedding light on its multifaceted mechanisms and in vivo applicability.

Unraveling the Mechanisms of Ch-SeNP Cytotoxicity against Cancer Cells: Insights from Targeted and Untargeted Metabolomics.

Although chitosan-stabilized selenium nanoparticles (Ch-SeNPs) have emerged as a promising chemical form of selenium for anticancer purposes, gathering more profound knowledge related to molecular dysfunctions contributes significantly to the promotion of their evolution as a chemotherapeutic drug. In this sense, metabolites are the end products in the flow of gene expression and, thus, the most sensitive to changes in the physiological state of a biological system. Therefore, metabolomics provides a functional readout of the biochemical activity and cell state. In the present study, we evaluated alterations in the metabolomes of HepG2 cells after the exposure to Ch-SeNPs to elucidate the biomolecular mechanisms involved in their therapeutic effect. A targeted metabolomic approach was conducted to evaluate the levels of four of the main energy-related metabolites (adenosine triphosphate (ATP); adenosine diphosphate (ADP); nicotinamide adenine dinucleotide (NAD+); and 1,4-dihydronicotinamide adenine dinucleotide (NADH)), revealing alterations as a result of exposure to Ch-SeNPs related to a shortage in the energy supply system in the cell. In addition, an untargeted metabolomic experiment was performed, which allowed for the study of alterations in the global metabolic profile as a consequence of Ch-SeNP exposure. The results indicate that the TCA cycle and glycolytic pathways were impaired, while alternative pathways such as glutaminolysis and cysteine metabolism were upregulated. Additionally, increased fructose levels suggested the induction of hypoxia-like conditions. These findings highlight the potential of Ch-SeNPs to disrupt cancer cell metabolism and provide insights into the mechanisms underlying their antitumor effects.

Capabilities of Single Cell ICP-MS for the Analysis of Cell Suspensions from Solid Tissues.

Single cell elemental (SC) analysis of isogenic cell cultures can be done using inductively coupled plasma (ICP-MS) detection. However, 2D cell cultures are just models to simplify the complexity of real tissue samples. Here, we show for the first time the capabilities of the technique (SC-ICP-MS) to analyze single cell suspensions of isolated cells from tissues. An optimized cocktail of proteolytic and collagenolytic enzymes was applied in a single preparation step with cellular yields up to 28% using 0.5 g of fresh rat spleen and liver, respectively. The retrieved cells revealed adequate morphology and stability to be examined by SC-ICP-MS. Quantitative elemental analysis of P, S, Cu, and Fe from disaggregated cells from rat spleen and liver tissues revealed levels of Fe of 7-16 fg/cell in the spleen and 8-12 fg/cell in the liver, while Cu was about 3-5 fg/cell in the spleen and 1.5-2.5 fg/cell in the liver. Evaluation of the transmembrane protein transferrin receptor 1 (TfR1) expression levels in disaggregated cells was also conducted by using a Nd-labelled antibody against this cell surface biomarker. Quantitative results showed significantly lower expression in the disaggregated cells than in the cell model HepG2, in agreement with the overexpression of this biomarker in tumor cells. In this proof of concept study, the tissue disaggregation protocol has shown to maintain the elemental intracellular content of cells as well as the presence of relevant antigens. This opens a completely new area of research for SC-ICP-MS in tissue samples as a complementary strategy with validation capabilities.

Children’s adverse experiences and psychotic chronification.

Research evidence points to a critical period of about five years after the first psychotic episode, being its resolution of utmost importance for the chronicity of the disorder. In addition, several studies suggest the high correlation between adult psychosis and childhood adversity, and a dose-response relationship in severity level.

Experiencias adversas infantiles ycronificación psicótica / Children’s adverse experiences and psychotic chronification

Introducción. La evidencia apunta a un período crítico dealrededor de cinco años tras el primer episodio psicótico decuya resolución depende la cronicidad del trastorno. Además,diversos estudios apuntan la elevada correlación entre psicosis adulta y adversidad infantil, y una relación dosis-respuesta en nivel de gravedad.El objetivo de la presente investigación es determinarla relación dosis-respuesta entre la psicosis adulta y la adversidad infantil y ponerla en relación con la resolución delperíodo crítico.Método. La muestra se obtuvo entre 45 pacientes a tratamiento en el Hospital Universitario San Agustín que habíanexperimentado algún episodio psicótico. Se aplicaron cuestionarios para el análisis de la psicopatología, la adversidadinfantil y otras variables sociodemográficas y clínicas.Resultados. Los resultados confirman la relación entrefrecuencia de adversidad infantil y cronificación psicótica.Conclusiones. Nuestra investigación pone de manifiestola importancia de la adversidad infantil en el futuro cursode una psicosis y destaca la importancia de recoger estos aspectos en la anamnesis. (AU)

Introduction. Research evidence points to a critical period of about five years after the first psychotic episode, beingits resolution of utmost importance for the chronicity of thedisorder. In addition, several studies suggest the high correlation between adult psychosis and childhood adversity, anda dose-response relationship in severity level.This research aims to determine the dose-response relationship between adult psychosis and put it in relation to theresolution of the critical period.Method. The sample was obtained among 45 patientsundergoing treatment at the San Agustín University Hospital who experienced some psychotic episode. Questionnaireswere applied for the analysis of psychopathology, childhoodadversity and other sociodemographic and clinical variables.Results. The results confirm the relationship between thefrequency of childhood adversity and psychotic chronification.Conclusions. Our research highlights the importance ofchildhood adversity in the future course of a psychosis andhighlights the importance of anamnesis focusing this regard. (AU)

Efecto del entrenamiento de la musculatura inspiratoria con válvula umbral sobre la capacidad funcional en mujeres físicamente activas mayores de 60 años / Effect of inspiratory muscle training with threshold valve on functional capacity of physically active women who are older than 60 years of age

Resumen Introducción: Los cambios fisiológicos asociados al envejecimiento generan una serie de modificaciones funcionales, destacando una disminución en la capacidad respiratoria. En este sentido, una estrategia alternativa para mejorar tal condición podría ser el entrenamiento de la musculatura inspiratoria (EMI). Objetivo: Analizar el efecto del EMI con válvula umbral, sobre la capacidad funcional en mujeres físicamente activas mayores de 60 años. Materiales y métodos: Se realizó un EMI con válvula umbral durante 4 semanas, sobre un grupo experimental (GE; n:10), contrastado con un grupo control (GC; n:5). Se valoraron las siguientes variables hemodinámicas y antropométricas: peso, talla, índice de masa corporal (IMC), lactato, doble producto y capacidad funcional, analizando los cambios pre y post entrenamiento. Resultados: en el grupo GE disminuye post intervención la concentración de lactato y la escala de percepción del esfuerzo; 3,16±0,51 a 2,5±0,39 y 5,56 ± 1,81 a 4±2, respectivamente. En el mismo grupo se incrementan los valores de presión inspiratoria máxima (Pimáx) post intervención; 42,11±14,57 a 60,44±14,47. El GC no presentó cambios en sus valores. Conclusión: No se evidencian cambios favorables en los metros recorridos post intervención, sin embargo, el EMI mostró una disminución sobre la concentración de lactato post ejercicio, lo que podría identificar un retraso en la aparición de la fatiga.

Abstract Introduction: Physiological changes associated with aging generate a series of functional modifications, mainly a decrease in respiratory capacity. In this regard, an alternative strategy to improve such a condition could be inspiratory muscle training (IMT). Objective: To analyze the effect of IMT with threshold valve on the functional capacity of physically active women who are older than 60 years of age. Materials and methods: IMT with threshold valve was carried out over a period of 4 weeks, comparing data from the experimental group (GE; n:10) to the control group (GC; n:5). The following hemodynamic and anthropometric variables were assessed: weight, height, body mass index (BMI), lactate, double product (DP) and functional capacity. Pre and post training changes were evaluated. Results: The GE group showed a decrease in both post-intervention lactate concentration (from 3.16±0.51 to 2.5±0.39) and effort perception scale (from 5.56 ± 1.81 to 4±2). On the other hand, this group experienced a post-intervention increase in maximal inspiratory pressure (MIP) from 42.11±14.57 to 60.44±14.47. The GC group did not present changes in its values. Conclusion: Although no evidence was found regarding favorable changes in the walked distance post-intervention, IMT induced a reduction in post-exercise lactate concentration, which could indicate a delay of onset of fatigue.

Complementary techniques (spICP-MS, TEM, and HPLC-ICP-MS) reveal the degradation of 40 nm citrate-stabilized Au nanoparticles in rat liver after intraperitoneal injection.

BACKGROUND: Due to the increased use of engineered nanoparticles (NPs), their tracing in environmental and biological systems is of utmost importance. Besides their accumulation within a biological specimen, little is known about their degradation and transformation into corresponding low-molecular species that might influence any toxicological impact. ANALYTICAL METHODS: Wistar rats underwent intraperitoneal injections of 40 nm citrate-stabilized gold nanoparticles. Different liver samples were analysed for the occurrence of nanoparticles and potential degradation products by means of spICP-MS, TEM and HPLC-ICP-MS. MAIN FINDINGS: Studies using spICP-MS revealed the presence of the originally administrated Au NPs (40 nm diameter) and some evidences of other Au-containing species due to the increased background signal. Images obtained by transmission electron microscopy (TEM) showed the predominant presence of particles of significantly smaller diameter (6 ± 2 nm). As complementary method, HPLC-ICP-MS confirmed the presence of both particle types indicating a degradation of the Au NPs accompanied by detection of low-molecular Au species. CONCLUSIONS: This study underlines that degradation of gold nanoparticles to low-molecular gold species might have to be taken into account in future for studies on their toxicological behaviour and their potential use in clinical applications.

Cytosolic copper is a major modulator of germination, development and secondary metabolism in Streptomyces coelicolor.

Streptomycetes are important biotechnological bacteria with complex differentiation. Copper is a well-known positive regulator of differentiation and antibiotic production. However, the specific mechanisms buffering cytosolic copper and the biochemical pathways modulated by copper remain poorly understood. Here, we developed a new methodology to quantify cytosolic copper in single spores which allowed us to propose that cytosolic copper modulates asynchrony of germination. We also characterised the SCO2730/2731 copper chaperone/P-type ATPase export system. A Streptomyces coelicolor strain mutated in SCO2730/2731 shows an important delay in germination, growth and sporulation. Secondary metabolism is heavily enhanced in the mutant which is activating the production of some specific secondary metabolites during its whole developmental cycle, including germination, the exponential growth phase and the stationary stage. Forty per cent of the S. coelicolor secondary metabolite pathways, are activated in the mutant, including several predicted pathways never observed in the lab (cryptic pathways). Cytosolic copper is precisely regulated and has a pleiotropic effect in gene expression. The only way that we know to achieve the optimal concentration for secondary metabolism activation, is the mutagenesis of SCO2730/2731. The SCO2730/2731 genes are highly conserved. Their inactivation in industrial streptomycetes may contribute to enhance bioactive compound discovery and production.

Plasmon-enhanced Raman scattering by carbon nanotubes optically coupled with near-field cavities.

We realize the coupling of carbon nanotubes as a one-dimensional model system to near-field cavities for plasmon-enhanced Raman scattering. Directed dielectrophoretic assembly places single-walled carbon nanotubes precisely into the gap of gold nanodimers. The plasmonic cavities enhance the Raman signal of a small nanotube bundle by a factor of 10(3). The enhanced signal arises exclusively from tube segments within the cavity as we confirm by spatially resolved Raman measurements. Through the energy and polarization of the excitation we address the extrinsic plasmonic and the intrinsic nanotube optical response independently. For all incident light polarizations, the nanotube Raman features arise from fully symmetric vibrations only. We find strong evidence that the signal enhancement depends on the orientation of the carbon nanotube relative to the cavity axis.

Use of a gold reflecting-layer in optical antenna substrates for increase of photoluminescence enhancement.

We report on a straightforward way to increase the photoluminescence enhancement of nanoemitters induced by optical nanotantennas. The nanoantennas are placed above a gold film-silica bilayer, which produces a drastic increase of the scattered radiation power and near field enhancement. We demonstrate this increase via photoluminescence enhancement using an organic emitter of low quantum efficiency, Tetraphenylporphyrin (TPP). An increase of the photoluminescence enhancement by a factor larger than three is observed compared to antennas without the reflecting-layer. In addition, we study the possibility of influencing the polarization of the light emitted by utilizing asymmetry of dimer antennas.

Polarized plasmonic enhancement by Au nanostructures probed through Raman scattering of suspended graphene.

We characterize plasmonic enhancement in a hotspot between two Au nanodisks using Raman scattering of graphene. Single layer graphene is suspended across the dimer cavity and provides an ideal two-dimensional test material for the local near-field distribution. We detect a Raman enhancement of the order of 10(3) originating from the cavity. Spatially resolved Raman measurements reveal a near-field localization one order of magnitude smaller than the wavelength of the excitation, which can be turned off by rotating the polarization of the excitation. The suspended graphene is under tensile strain. The resulting phonon mode softening allows for a clear identification of the enhanced signal compared to unperturbed graphene.

Controlling light localization and light-matter interactions with nanoplasmonics.

Nanoplasmonics is the emerging research field that studies light-matter interactions mediated by resonant excitations of surface plasmons in metallic nanostructures. It allows the manipulation of the flow of light and its interaction with matter at the nanoscale (10(-9) m). One of the most promising characteristics of plasmonic resonances is that they occur at frequencies corresponding to typical electronic excitations in matter. This leads to the appearance of strong interactions between localized surface plasmons and light emitters (such as molecules, dyes, or quantum dots) placed in the vicinity of metals. Recent advances in nanofabrication and the development of novel concepts in theoretical nanophotonics have opened the way to the design of structures aimed to reduce the lifetime and enhance the decay rate and quantum efficiency of available emitters. In this article, some of the most relevant experimental and theoretical achievements accomplished over the last several years are presented and analyzed.