Particulate matter and ultrafine particles in urban air pollution and their effect on the nervous system.

According to the World Health Organization, both indoor and urban air pollution are responsible for the deaths of around 3.5 million people annually. During the last few decades, the interest in understanding the composition and health consequences of the complex mixture of polluted air has steadily increased. Today, after decades of detailed research, it is well-recognized that polluted air is a complex mixture containing not only gases (CO, NOx, and SO2) and volatile organic compounds but also suspended particles such as particulate matter (PM). PM comprises particles with sizes in the range of 30 to 2.5 µm (PM30, PM10, and PM2.5) and ultrafine particles (UFPs) (less than 0.1 µm, including nanoparticles). All these constituents have different chemical compositions, origins and health consequences. It has been observed that the concentration of PM and UFPs is high in urban areas with moderate traffic and increases in heavy traffic areas. There is evidence that inhaling PM derived from fossil fuel combustion is associated with a wide variety of harmful effects on human health, which are not solely associated with the respiratory system. There is accumulating evidence that the brains of urban inhabitants contain high concentrations of nanoparticles derived from combustion and there is both epidemiological and experimental evidence that this is correlated with the appearance of neurodegenerative human diseases. Neurological disorders, such as Alzheimer's and Parkinson's disease, multiple sclerosis, and cerebrovascular accidents, are among the main debilitating disorders of our time and their epidemiology can be classified as a public health emergency. Therefore, it is crucial to understand the pathophysiology and molecular mechanisms related to PM exposure, specifically to UFPs, present as pollutants in air, as well as their correlation with the development of neurodegenerative diseases. Furthermore, PM can enhance the transmission of airborne diseases and trigger inflammatory and immune responses, increasing the risk of health complications and mortality. Therefore, understanding the different levels of this issue is important to create and promote preventive actions by both the government and civilians to construct a strategic plan to treat and cope with the current and future epidemic of these types of disorders on a global scale.

Effects of Co-Solvent Nature and Acid Concentration in the Size and Morphology of Wrinkled Mesoporous Silica Nanoparticles for Drug Delivery Applications.

Hierarchically porous materials, such as wrinkled mesoporous silica (WMS), have gained interest in the last couple of decades, because of their wide range of applications in fields such as nanomedicine, energy, and catalysis. The mechanism of formation of these nanostructures is not fully understood, despite various groups reporting very comprehensive studies. Furthermore, achieving particle diameters of 100 nm or less has proven difficult. In this study, the effects on particle size, pore size, and particle morphology of several co-solvents were evaluated. Additionally, varying concentrations of acid during synthesis affected the particle sizes, yielding particles smaller than 100 nm. The morphology and physical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Homogeneous and spherical WMS, with the desired radial wrinkle morphology and particle sizes smaller than 100 nm, were obtained. The effect of the nature of the co-solvents and the concentration of acid are explained within the frame of previously reported mechanisms of formation, to further elucidate this intricate process.

Respiratory immune system and consequences due to particulate matter in air pollution / Sistema inmune respiratorio y consecuencias de contaminación aérea por materia particulada

The respiratory system is commonly known for being responsible for gaseous exchange. However, chronic exposure to air born pollution increases each year the number of asthma, chronic obstructive pulmonary disease (COPD), and lung cancer cases, which compels us to view the lung as a vulnerable organ due to the fact that because of its nature it enters in contact with substances present in the environment. Fortunately, the immune response mechanism acts locally in the lung in order to modulate the inflammatory response and to facilitate the clearance of inhaled pathogens, as well as volatile organic compounds (VOCs), metals, sulphur and nitrogen oxides, ozone and particulate matter (PM). Expanding our understanding of the molecular mechanisms underlying inflammation and pathology induced by airborne contaminant particles in the long term can help to develop strategies to reduce the risks of exposure to some of the most hazardous air pollutants, as well as to reduce the toxicity of nanomaterials and may also help to identify therapeutic targets to be used in the preventive treatment of susceptible groups.

El sistema respiratorio es comúnmente conocido por ocuparse del intercambio gaseoso; sin embargo, la exposición crónica a contaminantes del aire aumenta cada año el número de casos nuevos de asma, enfermedad pulmonar obstructiva crónica (EPOC) y cáncer de pulmón, lo que nos obliga a ver el pulmón como un órgano vulnerable, ya que por su naturaleza entra en contacto con sustancias presentes en el medio ambiente. Afortunadamente, el mecanismo de respuesta inmune actúa localmente en el pulmón para modular respuestas inflamatorias y para facilitar el aclaramiento de patógenos inhalados, así como de compuestos orgánicos volátiles (VOCs, por sus siglas en inglés), metales, óxidos de azufre y nitrógeno, ozono y materia particulada (PM, por sus siglas en inglés). Ampliar nuestra comprensión de los mecanismos moleculares que subyacen a la inflamación y a la patología inducida por partículas contaminantes en las vías respiratorias a largo plazo puede ayudar a desarrollar estrategias para reducir los riesgos de exposición a algunos de los contaminantes atmosféricos más peligrosos, así como a reducir la toxicidad de los nanomateriales y quizás pueda también ayudar a identificar objetivos terapéuticos que se puedan utilizar en el tratamiento preventivo de grupos susceptibles.