In vitro toxicity of fine and coarse particulate matter on the skin, ocular and lung microphysiological cell-culture systems.

Particulate matter (PM) has been associated with adverse effects on human health, causing allergies, skin and eye irritation and corrosion, respiratory tract irritation, headaches, bronchoconstriction, cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), lung cancer, reproductive problems, premature deaths, and epigenetic changes that lead to a wide variety of cancers, among other health conditions. The air quality in the Medellín - Colombia presents fluctuations that oscillate between the maximum permissible levels established at the national level and by the WHO, which represents a latent risk to people's health. Although important efforts have been made to quantify the different levels of pollution and administrative measures have been established to mitigate air pollution, little research work has been done to establish the relationship between these levels of pollutants and the effects on biological systems. The objective of the present research was to make a morphological and chemical characterization of particulate matter (PM) captured with a commercial air filter and a electrospun nanofiber membrane and evaluate the cytotoxicity of the each PM extracts in monolayer and co-culture models which recreate microphysiological systems of lung, skin and cornea and propose the possible cellular interactions that lead the cytotoxic response of the chemical compounds found in particulate matter in cities. The morphology and elemental chemical characterization were done with scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM - EDS). For the polycyclic aromatic hydrocarbons detection was made with a chromatographic method accoupled to mass spectrometer. Finally, the cytotoxicity was made in monolayers of A549, HEK001, and SIRC cell lines and microphysiological systems consisting of two-cell layer construct to resemble the interaction between fibroblast and epithelial cells that comprises naturally the corneal, skin and lung tissue. We performed three different cocultures models with BALB/3T3 clone A31 as a feeder layer, using porous Transwell® inserts in the in-contact and non-contact way. Monolayer and co-culture models were exposed to coarse and fine PM (1, 2, and 5 mg/mL) and the cell viability was evaluated at 24 h using an MTT assay. The electrospun nanofibers membranes demonstrates higher efficiency to capture PM with different sizes and high concentration of polycyclic aromatic hydrocarbons, heavy metals, and other chemical compounds responsible of many human diseases. Cytotoxic effects of MP were observed in all models at higher concentration; however, models exposed to fine PM exhibited a significant reduction in cell viability compared to those exposed to coarse PM. In addition, multilayer models are more resistant to PM exposure than monolayer models. Furthermore, the study indicated that, depending on the seeding strategy, different results might be observed: the non-contact model showed higher resistance to PM exposure than in-contact for SIRC and HEK001, but A549 monolayers showed the highest viability response. This study demonstrates the usefulness of applying co-culture models to assess environmental pollutant toxicity, in addition to being a potential alternative method to animal testing for risk assessment.

Actividad antiséptica de vinagre de Guadua angustifolia Kunth / Antiseptic activity of Guadua angustifolia Kunth vinegar

Introducción: los vinagres de bambú se utilizan en los países orientales en aplicaciones farmacéuticas, con la especie Guadua angustifolia Kunth no se han encontrado investigaciones similares. Evaluar la actividad antiséptica del vinagre de guadua permitiría avanzar en estos desarrollos. Objetivo: determinar la sensibilidad de las bacterias Pseudomona aeruginosa y Staphylococcus aureus frente al vinagre de guadua, los cambios con la concentración y el pH. Métodos: la actividad antimicrobiana se midió por difusión en agar en medio Muller Hinton. Se ensayaron vinagres a concentraciones entre 100, 80, 60, 40 y 20 por ciento a pH entre 3 y 6. Se estableció la concentración mínima inhibitoria. Resultados: el vinagre de guadua presenta actividad antiséptica a concentraciones superiores a 12 mg/mL en base seca, rango de pH 2 a 6, reduce en 4 log la concentración de microorganismos y muestra mayor actividad antiséptica contra S. aureus. Conclusiones: la actividad antiséptica del vinagre de bambú comparado con el de otra especie, obtenido en condiciones similares a las que se realizaron en este estudio, se obtiene una mayor actividad para el vinagre de G. angustifolia, lo cual permite demostrar el gran potencial de este para el desarrollo de formulaciones con actividad antiséptica.

Introduction: bamboo vinegars are used in the Asian countries for pharmaceutical applications, but the Guadua angustifolia Kunth species has not been similarly researched in this field. The assessment of the antiseptic activity of guadua vinegar would allow moving forward in this direction. Objective: to determine the antiseptic action of guadua vinegar against Pseudomona aeruginosa and Staphylococcus aureus bacteria, with several changes in concentration and the pH. Methods: the antimicrobial activity was measured through the agar diffusion in Muller Hinton medium. Guadua vinegars were tested at 100, 80, 60, 40, and 20 percent concentrations and the pH ranged 3 to 6. The minimum inhibitory concentration was set. Results: guadua vinegar showed antiseptic properties at concentrations over 12 mg/mL, on dry weight and pH range of 2 to 6; it reduced by 4 log the final microorganism concentration and exhibited greater antibacterial activity against S. aureus. Conclusions: comparing the antiseptic activity of bamboo vinegar with that of another species, under conditions similar to those in this study, results in greater activity for Guadua angustifolia vinegar, which can prove its great potential for the development of antiseptic formulations.