The search for new strategies to curb the spread of the SARS-CoV-2 coronavirus, which causes COVID-19, has become a global priority. Various nanomaterials have been proposed as ideal candidates to inactivate the virus; however, because of the high level of biosecurity required for their use, alternative models should be determined. This study aimed to compare the effects of two types of nanomaterials gold (AuNPs) and silver nanoparticles (AgNPs), recognized for their antiviral activity and affinity with the coronavirus spike protein using PhiX174 and enveloped Phi6 bacteriophages as models. To reduce the toxicity of nanoparticles, a species known for its intermediate antiviral activity, Solanum mammosum L. (Sm), was used. NPs prepared with sodium borohydride (NaBH₄) functioned as the control. Antiviral activity against PhiX174 and Phi6 was analyzed using its seed, fruit, leaves, and essential oil; the leaves were the most effective on Phi6. Using the aqueous extract of the leaves, AuNPs-Sm of 5.34 ± 2.25 nm and AgNPs-Sm of 15.92 ± 8.03 nm, measured by transmission electron microscopy, were obtained. When comparing NPs with precursors, both gold(III) acetate and silver nitrate were more toxic than their respective NPs (99.99% at 1 mg ml⁻¹). The AuNPs-Sm were less toxic, reaching 99.30% viral inactivation at 1 mg ml⁻¹, unlike the AgNPs-Sm, which reached 99.94% at 0.01 mg ml⁻¹. In addition, cell toxicity was tested in human adenocarcinoma alveolar basal epithelial cells (A549) and human foreskin fibroblasts. Gallic acid was the main component identified in the leaf extract using high performance liquid chromatography with diode array detection (HPLC-DAD). The FT-IR spectra showed the presence of a large proportion of polyphenolic compounds, and the antioxidant analysis confirmed the antiradical activity. The control NPs showed less antiviral activity than the AuNPs-Sm and AgNPs-Sm, which was statistically significant; this demonstrates that both the S. mammosum extract and its corresponding NPs have a greater antiviral effect on the surrogate Phi bacteriophage, which is an appropriate model for studying SARS-CoV-2.

Background: Nanoparticles are structures up to 100 nm in size. Estimation of their size is usually determined by assessing of images obtained from scanning electron microscopy (SEM) and/or transmission electron microscopy (TEM) techniques. Studies on the effect of visual cognition on the analysis of these types of images are limited. Objective: The aim of the research was to determine whether students’ visual cognition influences the identification, analysis, and measurement of nanoparticle size through SEM and TEM imaging using ImageJ software. Methods: The visual cognition of each participant was evaluated by recognizing individual nanoparticles and measuring their diameter using ImageJ software. Finally, the Kruskal Wallis test was performed for statistical analysis. Results: Participants applied or not four main identification criteria in order to identify individual nanoparticles: shape, high contrast, defined edges, and presence/absence of agglomerates, being “shape” the predominant parameter taken into account to measure the diameter using ImageJ. Average diameters, number of measured nanoparticles, and standard errors of measurements varied between groups in all analyzed images, evidencing the influence of visual cognition on the measurements. Conclusion: We conclude that there is an effect of visual cognition in the identification of nanoparticles and their diameter estimation. The user’s training, background, experience, perspective, and operational conditions of SEM/TEM play a fundamental role in estimating the size of nanoparticles measured in microphotographs using ImageJ.

The quality of fuel depends on its chemical composition, which influences engine performance. Gas chromatography, a cornerstone of global oil and fuel R&D, remains crucial for ensuring the quality of petroleum products and regulatory compliance. Scientists use the most accurate analysis (PIONA) as a tool derived from gas chromatography coupled with mass spectrometry to identify and quantify hydrocarbons that influence resistance to detonation, which is determined by the research octane number (RON). This study introduces the “average carbon number (ACN)”, calculated from the molar chemical composition of commercial gasoline samples sold in Ecuador (Extra gasoline and Súper gasoline). A quantitative comparison of the ACN with techniques applied using standardized international procedures reveals that the ACN characterizes gasoline samples by providing insight into the distribution shape of carbon graphs. A comprehensive statistical analysis demonstrates the potential usefulness of ACN in characterizing fuel composition, highlighting its relevance in broader fuel quality assessments without the need for carbon distribution plots.

Debido a la importancia de una alternativa en decoloración de aguas residuales provenientes de la industria de alimentos, se reporta la remoción del colorante tartrazina, utilizando nanopartículas de hierro cerovalentes. Las nanopartículas se prepararon por reducción química de cloruro férrico con borohidruro de sodio en medio inerte. Para evaluar la remoción, se emplearon concentraciones de 25, 50 100, 150 y 200 mg/L de nanopartículas, con tiempos de contacto en agua de 10, 20 y 30 minutos a pH de 3, 5, 7, 9 y 11. Las nanopartículas obtenidas se caracterizaron por Microscopía Electrónica de Barrido (SEM, por sus siglas en inglés) y Espectrómetro de Dispersión de Rayos X (EDX, por sus siglas en inglés). Como resultados se obtuvieron nanopartículas de 53,3 y 92,1 nm aproximadamente. Se verificó la remoción de los colorantes en agua por Espectrofotometría UV-Vis e Infrarrojos con Transformada de Fourier (FT-IR). Los parámetros óptimos para la remoción de tartrazina, se lograron empleando 200 mg/L de nanopartículas, 30 minutos de agitación y pH 3 con una eficiencia del 83,3 %. Se logró una adsorción de tartrazina de hasta 301 mmol/100g (1659 mg/g). Se concluye que el uso de nanopartículas de hierro cerovalentes, es adecuado para la remoción del colorante tartrazina en agua.

Se han descrito muchos estudios de biosíntesis de nanopartículas de plata usando el extracto del bulbo de ajo (Allium sativum) como agente reductor. Sin embargo, el uso de sus hojas es poco conocido, por considerarse un producto de desecho. En este estudio, se comparó el tamaño de nanopartículas de plata obtenidas con el extracto acuoso de las hojas de ajo usando dos técnicas diferentes de calentamiento: placa y por microondas. Las nanopartículas obtenidas se caracterizaron por espectrofotometría UV-Visible, microscopía de transmisión electrónica (TEM, por sus siglas en inglés), dispersión dinámica de luz (DLS, por sus siglas en inglés) y difracción de rayos X (XRD, por sus siglas en inglés). Como resultado se obtuvieron nanopartículas con un tamaño promedio de 15,4±7,9 y 9,9±10,5 nm empleando las dos técnicas respectivamente. De acuerdo al análisis estadístico realizado, se demostró que existen diferencias significativas en relación al tamaño de nanopartícula obtenido. Se concluye que el extracto acuoso de las hojas de la planta de ajo, es un agente reductor adecuado para la síntesis de nanopartículas de plata, y que la técnica de microondas es más efectiva por la rapidez y tamaño de nanopartículas obtenidas.

Background: Natural and synthetic polymeric materials can be used in the fields of biomedicine and pharmaceuticals as a material for controlled drug delivery. Among the synthetic polymers, polyesters are synthesized from two natural monomers: lactic and glycolic acid, which are biocompatible and biodegradable. Objective: Here we review broad aspects of polyesters including its properties, synthesis, characterization, and particle drug delivery applications. Conclusion: Finally, we have concluded that polyesters are certainly very versatile material that is continuously reinvented for future application in new areas of science and medicine. However, several aspects must be considered when synthesizing polyesters, which have a direct influence on biodegradability and biocompatibility. These properties may limit the performance of in vitro and in vivo tests.