The role of potassium current in the pulmonary response to environmental oxidative stress.

Exposure of human lung epithelial cells (A549 cell line) to the oxidant pollutant ozone (O3) alters cell membrane currents inducing its decrease, when the cell undergoes to a voltage-clamp protocol ranging from -90 to +70mV. The membrane potential of these cells is mainly maintained by the interplay of potassium and chloride currents. Our previous studies indicated the ability of O3 to activate ORCC (Outward Rectifier Chloride Channel) and consequently increases the chloride current. In this paper our aim was to understand the response of potassium current to oxidative stress challenge and to identify the kind potassium channel involved in O3 induced current changes. After measuring the total membrane current using an intracellular solution with or without potassium ions, we obtained the contribution of potassium to the overall membrane current in control condition by a mathematical approach. Repeating these experiments after O3 treatment we observed a significant decrease of Ipotassium. Treatment of the cells with Iberiotoxin (IbTx), a specific inhibitor of BK channel, we were able to verify the presence and the functionality of BK channels. In addition, the administration of 4-Aminopyridine (an inhibitor of voltage dependent K channels but not BK channels) and Tetraethylammonium (TEA) before and after O3 treatment we observed the formation of BK oxidative post-translation modifications. Our data suggest that O3 is able to inhibit potassium current by targeting BK channel. Further studies are needed to better clarify the role of this BK channel and its interplay with the other membrane channels under oxidative stress conditions. These findings can contribute to identify the biomolecular pathway induced by O3 allowing a possible pharmacological intervention against oxidative stress damage in lung tissue.

Dimethyl Fumarate-Loaded Transethosomes: A Formulative Study and Preliminary Ex Vivo and In Vivo Evaluation.

In this study, transethosomes were investigated as potential delivery systems for dimethyl fumarate. A formulative study was performed investigating the effect of the composition of transethosomes on the morphology and size of vesicles, as well as drug entrapment capacity, using cryogenic transmission electron microscopy, photon correlation spectroscopy, and HPLC. The stability of vesicles was evaluated, both for size increase and capability to control the drug degradation. Drug release kinetics and permeability profiles were evaluated in vitro using Franz cells, associated with different synthetic membranes. The in vitro viability, as well as the capacity to improve wound healing, were evaluated in human keratinocytes. Transmission electron microscopy enabled the evaluation of transethosome uptake and intracellular fate. Based on the obtained results, a transethosome gel was further formulated for the cutaneous application of dimethyl fumarate, the safety of which was evaluated in vivo with a patch test. It was found that the phosphatidylcholine concentration affected vesicle size and lamellarity, influencing the capacity to control dimethyl fumarate's chemical stability and release kinetics. Indeed, phosphatidylcholine 2.7% w/w led to multivesicular vesicles with 344 nm mean size, controlling the drug's chemical stability for at least 90 days. Conversely, phosphatidylcholine 0.9% w/w resulted in 130 nm sized unilamellar vesicles, which maintained 55% of the drug over 3 months. These latest kinds of transethosomes were able to improve wound healing in vitro and were easily internalised by keratinocytes. The selected transethosome gel, loading 25 mg/mL dimethyl fumarate, was not irritant after cutaneous application under occlusion, suggesting its possible suitability in the treatment of wounds caused by diabetes mellitus or peripheral vascular diseases.

Involvement of the TREK-1 channel in human alveolar cell membrane potential and its regulation by inhibitors of the chloride current.

K+ channels of the alveolar epithelium control the driving force acting on the ionic and solvent flow through the cell membrane contributing to the maintenance of cell volume and the constitution of epithelial lining fluid. In the present work, we analyze the effect of the Cl- channel inhibitors: (4-[(2-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-inden-5-yl)oxy] butanoic acid (DCPIB) and 9-anthracenecarboxylic acid (9-AC) on the total current in a type II pneumocytes (A549 cell line) model by patch clamp, immunocytochemical, and gene knockdown techniques. We noted that DCPIB and 9-AC promote the activation of K conductance. In fact, they significantly increase the intensity of the current and shift its reversal potential to values more negative than the control. By silencing outward rectifier channel in its anoctamin 6 portion, we excluded a direct involvement of Cl- ions in modulation of IK and, by means of functional tests with its specific inhibitor spadin, we identified the TREK-1 channel as the presumable target of both drugs. As the activity of TREK-1 has a key role for the correct functioning of the alveolar epithelium, the identification of DCPIB and 9-AC molecules as its activators suggests their possible use to build new pharmacological tools for the modulation of this channel.

Role of Nrf2 in preventing oxidative stress induced chloride current alteration in human lung cells.

The lung tissue is one of the main targets of oxidative stress due to external sources and respiratory activity. In our previous work, we have demonstrated in that O3 exposure alters the Cl- current-voltage relationship, with the appearance of a large outward rectifier component mainly sustained by outward rectifier chloride channels (ORCCs) in human lung epithelial cells (A549 line). In the present study, we have performed patch clamp experiments, in order to identify which one of the O3 byproducts (4hydroxynonenal (HNE) and/or H2 O2 ) was responsible for chloride current change. While 4HNE exposition (up to 25 µM for 30' before electrophysiological analysis) did not reproduce O3 effect, H2 O2 produced by glucose oxidase 10 mU for 24 hr before electrophysiological analysis mimicked O3 response. This result was confirmed treating the cell with catalase (CAT) before O3 exposure (1,000 U/ml for 2 hr): CAT was able to rescue Cl- current alteration. Since CAT is regulated by Nrf2 transcription factor, we pre-treated the cells with the Nrf2 activators, resveratrol and tBHQ. Immunochemical and immunocytochemical results showed Nrf2 activation with both substances that lead to prevent OS effect on Cl- current. These data bring new insights into the mechanisms involved in OS-induced lung tissue damage, pointing out the role of H2 O2 in chloride current alteration and the ability of Nfr2 activation in preventing this effect.

Modulation of Chloride Currents in Human Lung Epithelial Cells Exposed to Exogenous Oxidative Stress.

Air pollution continues to be a major public health concern affecting 9 out of 10 individuals living in urban areas worldwide. Respiratory tract is the organ most exposed to gas pollution, and ozone has been shown to be one of the most noxious pollutants to which living organisms are exposed. In the present work, we have investigated the effects of 0.1 ppm of ozone on chloride currents in human lung epithelial cells (A549 line) and whether this effect could be modulated by vitamin E pre-treatment. Whole-cell patch clamp technique was applied to not excitable cells in order to obtain information about chloride currents behavior, important for epithelial lung cells homeostasis. Significant alteration of the I-V curve after ozone treatment was observed, with the appearance of a large outward rectifier component decreasing over time and returning to the basal state levels after 24 h. Statistical analysis indicated a modification of the amount of ions passing the membrane in the unit of time as a possible cause of this difference. RT-qPCR analysis showed an increase in ClC-2 and ORCC mRNA after ozone exposure. In addition, pre-treatment with vitamin E was able to suppress the outward rectifier component induced by ozone, bringing back the current values to the control level and preventing ozone induced chloride channels up regulation. Our data suggest that ozone exposure is able to modify chloride current density and the use of vitamin E can prevent the above-mentioned damage. J. Cell. Physiol. 232: 1817-1825, 2017. © 2016 Wiley Periodicals, Inc.

Mechanistic insight into CM18-Tat11 peptide membrane-perturbing action by whole-cell patch-clamp recording.

The membrane-destabilization properties of the recently-introduced endosomolytic CM18-Tat11 hybrid peptide (KWKLFKKIGAVLKVLTTG-YGRKKRRQRRR, residues 1-7 of cecropin-A, 2-12 of melittin, and 47-57 of HIV-1 Tat protein) are investigated in CHO-K1 cells by using the whole-cell configuration of the patch-clamp technique. CM18-Tat11, CM18, and Tat11 peptides are administered to the cell membrane with a computer-controlled micro-perfusion system. CM18-Tat11 induces irreversible cell-membrane permeabilization at concentrations (≥4 µM) at which CM18 triggers transient pore formation, and Tat11 does not affect membrane integrity. We argue that the addition of the Tat11 module to CM18 is able to trigger a shift in the mechanism of membrane destabilization from "toroidal" to "carpet", promoting a detergent-like membrane disruption. Collectively, these results rationalize previous observations on CM18-Tat11 delivery properties that we believe can guide the engineering of new modular peptides tailored to specific cargo-delivery applications.

Ethosomes for Curcumin and Piperine Cutaneous Delivery to Prevent Environmental-Stressor-Induced Skin Damage.

Diesel particulate matter is one of the most dangerous environmental stressors affecting human health. Many plant-derived compounds with antioxidant and anti-inflammatory properties have been proposed to protect the skin from pollution damage. Curcumin (CUR) has a plethora of pharmacological activities, including anticancer, antimicrobial, anti-inflammatory and antioxidant. However, it has low bioavailability due to its difficult absorption and rapid metabolism and elimination. CUR encapsulation in nanotechnological systems and its combination with biopotentiators such as piperine (PIP) can improve its pharmacokinetics, stability and activity. In this study, ethosomes (ETs) were investigated for CUR and PIP delivery to protect the skin from damage induced by diesel particulate matter. ETs were produced by different strategies and characterized for their size distribution by photon correlation spectroscopy, for their morphology by transmission electron microscopy, and for their drug encapsulation efficiency by high-performance liquid chromatography. Franz cells enabled us to evaluate in vitro the drug diffusion from ETs. The results highlighted that ETs can promote the skin permeation of curcumin. The studies carried out on their antioxidant activity demonstrated an increase in the antioxidant power of CUR using a combination of CUR and PIP separately loaded in ETs, suggesting their possible application for the prevention of skin damage due to exogenous stressors. Ex vivo studies on human skin explants have shown the suitability of drug-loaded ETs to prevent the structural damage to the skin induced by diesel engine exhaust exposure.

Topical Application of M89PF Containing Vichy Mineralising Water and Probiotic Fractions Prevents Cutaneous Damage Induced by Exposure to UV and O3.

Purpose: Exposure of the skin to ultraviolet radiation (UV) or ozone (O3) results in stressed skin, leading to the alteration of the skin physical barrier and defence functions. In this work, the preventive benefit of a dermocosmetic, M89PF, containing Vichy mineralising water, probiotic fractions, antioxidant vitamins and hyaluronic acid, in the alteration of skin physical barrier and skin defence functions after exposure to O3 and UV, alone or combined, was assessed. Methods: Untreated and treated (M89PF) skin explants were exposed to O3, to UV rays or to O3+UV. Immunofluorescence was performed for skin barrier, oxidative stress, and inflammatory markers after one and four days of exposure to the pollutants. Results: M89PF significantly (p≤0.05) prevented the decrease of the expression level of different skin barrier markers, and significantly (p≤0.05) prevented the induction of OxInflammatory markers and inflammasome components by UV, O3, or both combined. Conclusion: M89PF prevents skin barrier damage, as well as oxidative stress and inflammatory markers induced by exposome factors, such as UV, O3, or both combined.

Ethosomes and Transethosomes as Cutaneous Delivery Systems for Quercetin: A Preliminary Study on Melanoma Cells.

The present study is aimed to design ethosomes and transethosomes for topical administration of quercetin. To overcome quercetin low bioavailability, scarce solubility and poor permeability that hamper its pharmaceutical use, the drug was loaded in ethosomes and transethosomes based on different concentrations of phosphatidylcholine. Vesicle morphology was studied by cryogenic transmission electron microscopy, while size distribution and quercetin entrapment capacity were evaluated up to 3 months, respectively, by photon correlation spectroscopy and high-performance liquid chromatography. The antioxidant property was studied by photochemiluminescence test. Quercetin release and permeation was investigated in vitro, using Franz cells associated to different membranes. In vitro assays were conducted on human keratinocytes and melanoma cells to study the behavior of quercetin-loaded nano-vesicular forms with respect to cell migration and proliferation. The results evidenced that both phosphatidylcholine concentration and quercetin affected the vesicle size. Quercetin entrapment capacity, antioxidant activity and size stability were controlled using transethosomes produced by the highest amount of phosphatidylcholine. In vitro permeation studies revealed an enhancement of quercetin permeation in the case of transethosomes with respect to ethosomes. Notably, scratch wound and migration assays suggested the potential of quercetin loaded-transethosomes as adjuvant strategy for skin conditions.

Chemoresistive Sensors for Cellular Type Discrimination Based on Their Exhalations.

The detection of volatile organic compounds (VOCs) exhaled by human body fluids is a recent and promising method to reveal tumor formations. In this feasibility study, a patented device, based on nanostructured chemoresistive gas sensors, was employed to explore the gaseous exhalations of tumoral, immortalized, and healthy cell lines, with the aim of distinguishing their VOC patterns. The analysis of the device output to the cell VOCs, emanated at different incubation times and initial plating concentrations, was performed to evaluate the device suitability to identify the cell types and to monitor their growth. The sensors ST25 (based on tin and titanium oxides), STN (based on tin, titanium, and niobium oxides), and TiTaV (based on titanium, tantalum and vanadium oxides) used here, gave progressively increasing responses upon the cell density increase and incubation time; the sensor W11 (based on tungsten oxide) gave instead unreliable responses to all cell lines. All sensors (except for W11) gave large and consistent responses to RKO and HEK293 cells, while they were less responsive to CHO, A549, and CACO-2 ones. The encouraging results presented here, although preliminary, foresee the development of sensor arrays capable of identifying tumor presence and its type.

Inflammasome involvement in CS-induced damage in HaCaT keratinocytes.

Cigarette smoke (CS) alters cutaneous biological processes such as redox homeostasis and inflammation response that might be involved in promoting skin inflammatory conditions. Exposure to CS has also been linked to a destabilization of the NLRP3 inflammasome in pollution target tissues such as the lung epithelium, resulting in a more vulnerable immunological response to several exogenous and endogenous stimuli related to oxidative stress. Thus, CS has an adverse effect on host defense, increasing the susceptibility to develop lung infections and pathologies. In the skin, another direct target of pollution, inflammasome disorders have been linked to an increasing number of diseases such as melanoma, psoriasis, vitiligo, atopic dermatitis, and acne, all conditions that have been connected directly or indirectly to pollution exposure. The inflammasome machinery is an important innate immune sensor in human keratinocytes. However, the role of CS in the NLRP1 and NLRP3 inflammasome in the cutaneous barrier has still not been investigated. In the present study, we were able to determine in keratinocytes exposed to CS an increased oxidative damage evaluated by 4-HNE protein adduct and carbonyl formation. Of note is that, while CS inhibited NLRP3 activation, it was able to activate NLRP1, leading to an increased secretion of the proinflammatory cytokines IL-1ß and IL-18. This study highlights the importance of the inflammasome machinery in CS that more in general, in pollution, affects cutaneous tissues and the important cross-talk between different members of the NLRP inflammasome family.

Ubiquitination as a key regulatory mechanism for O3-induced cutaneous redox inflammasome activation.

NLRP1 is one of the major inflammasomes modulating the cutaneous inflammatory responses and therefore linked to a variety of cutaneous conditions. Although NLRP1 has been the first inflammasome to be discovered, only in the past years a significant progress was achieved in understanding the molecular mechanism and the stimuli behind its activation. In the past decades a crescent number of studies have highlighted the role of air pollutants as Particulate Matter (PM), Cigarette Smoke (CS) and Ozone (O3) as trigger stimuli for inflammasomes activation, especially via Reactive Oxygen Species (ROS) mediators. However, whether NLRP1 can be modulated by air pollutants via oxidative stress and the mechanism behind its activation is still poorly understood. Here we report for the first time that O3, one of the most toxic pollutants, activates the NLRP1 inflammasome in human keratinocytes via oxidative stress mediators as hydrogen peroxide (H2O2) and 4-hydroxy-nonenal (4HNE). Our data suggest that NLRP1 represents a target protein for 4HNE adduction that possibly leads to its proteasomal degradation and activation via the possible involvement of E3 ubiquitin ligase UBR2. Of note, Catalase (Cat) treatment prevented inflammasome assemble and inflammatory cytokines release as well as NLRP1 ubiquitination in human keratinocytes upon O3 exposure. The present work is a mechanistic study that follows our previous work where we have showed the ability of O3 to induce cutaneous inflammasome activation in humans exposed to this pollutant. In conclusion, our results suggest that O3 triggers the cutaneous NLRP1 inflammasome activation by ubiquitination and redox mechanism.

The Lesson Learned from the COVID-19 Pandemic: Can an Active Chemical Be Effective, Safe, Harmless-for-Humans and Low-Cost at a Time? Evidence on Aerosolized Hypochlorous Acid.

The COVID-19 pandemic has underlined the importance of disinfectants as tools to prevent and fight against coronavirus spreading. An ideal disinfectant and sanitizer must be nontoxic to surface contact, noncorrosive, effective, and relatively inexpensive as it is hypochlorous acid (HOCl). The present work intended to evaluate, on different surfaces, the bactericidal and virucidal effectiveness of nebulized HOCl and test its safety usage in 2D and 3D skin and lung models. Our data showed that HOCl at the dose of 300 ppm did not affect cellular and tissue viability, not their morphology. The HOCl bactericidal properties varies with the surface analyzed: 69% for semi-porous, 96-99.9% for flat and porous. This discrepancy was not noticed for the virucidal properties. Overall, this study showed that nebulized HOCl can prevent virus and bacteria growth without affecting lung and skin tissues, making this compound a perfect candidate to sanitize indoor environments.

Extra Virgin Olive Oil Extracts of Indigenous Southern Tuscany Cultivar Act as Anti-Inflammatory and Vasorelaxant Nutraceuticals.

Extra virgin olive oil (EVOO) is the typical source of fats in the Mediterranean diet. While fatty acids are essential for the EVOO nutraceutical properties, multiple biological activities are also due to the presence of polyphenols. In this work, autochthonous Tuscany EVOOs were chemically characterized and selected EVOO samples were extracted to obtain hydroalcoholic phytocomplexes, which were assayed to establish their anti-inflammatory and vasorelaxant properties. The polar extracts were characterized via 1H-NMR and UHPLC-HRMS to investigate the chemical composition and assayed in CaCo-2 cells exposed to glucose oxidase or rat aorta rings contracted by phenylephrine. Apigenin and luteolin were found as representative flavones; other components were pinoresinol, ligstroside, and oleuropein. The extracts showed anti-inflammatory and antioxidant properties via modulation of NF-κB and Nrf2 pathways, respectively, and good vasorelaxant activity, both in the presence and absence of an intact endothelium. In conclusion, this study evaluated the nutraceutical properties of autochthonous Tuscany EVOO cv., which showed promising anti-inflammatory and vasorelaxant effects.

A pressure-polishing set-up to fabricate patch pipettes that seal on virtually any membrane, yielding low access resistance and efficient intracellular perfusion.

When performing whole-cell configuration recordings, it is important to minimize series resistance to reduce the time constant of charging the cell membrane capacitance and to reduce error in membrane potential control. To this end, an existing method was improved by widening the patch pipette shank through the calibrated combination of heat and air pressure. The heat was produced by passing current through a filament that was shaped appropriately to ensure a homogeneous heating of the pipette shank. Pressurized air was applied to the lumen of a pipette, pulled from a borosilicate glass microcap, via the pressure port of a modified commercial holder. The pipette reshaping was viewed on an LCD monitor connected to a contrast-intensified CCD camera and coupled to a modified bright-field stereomicroscope. By appropriately regulating the timing of air pressure and the application of heating, the pipette shank and, independently, the tip opening diameter were widened as desired. The methods illustrated here to fabricate and use the patch pipettes, using just one glass type, allowed the sealing of a wide variety of cell types isolated from different amphibian, reptilian, fish, and mammalian tissues as well as a variety of artificial membranes made with many different lipid mixtures. The access resistance yielded by pressure-polished pipettes was approximately one-fourth the size of the one attained with conventional pipettes; besides improving the electrical recordings, this minimized intracellular ion accumulation or depletion as well. Enlarged shank geometry allowed for fast intracellular perfusion as shown by fluorescence imaging, also via pulled quartz or plastic tubes, which could be inserted very close to the pipette tip.

Deferoxamine Treatment Improves Antioxidant Cosmeceutical Formulation Protection against Cutaneous Diesel Engine Exhaust Exposure.

Skin is one of the main targets of the outdoor stressors. Considering that pollution levels are rising progressively, it is not surprising that several cutaneous conditions have been associated with its exposure. Among the pollutants, diesel engine exhaust (DEE) represents one of the most toxic, as it is composed of a mixture of many different noxious chemicals generated during the compression cycle, for ignition rather than an electrical spark as in gasoline engines. The toxic chemicals of most concern in DEE, besides the oxides of nitrogen, sulfur dioxide and various hydrocarbons, are metals that can induce oxidative stress and inflammation. The present study aimed to evaluate the effects of topical application, singularly or in combination, of the iron-chelator deferoxamine and a commercially available formulation, CE Ferulic, in up to 4-day DEE-exposed skin. DEE induced a significant increase in the oxidative marker 4-hydroxy-nonenal (4HNE) and matrix-metallopeptidase-9 (MMP-9), the loss of cutaneous-barrier-associated proteins (filaggrin and involucrin) and a decrease in collagen-1, while the formulations prevented the cutaneous damage in an additive manner. In conclusion, this study suggests that iron plays a key role in DEE-induced skin damage and its chelation could be an adjuvant strategy to reinforce antioxidant topical formulations.

Selective Fatty Acid Amide Hydrolase Inhibitors as Potential Novel Antiepileptic Agents.

Temporal lobe epilepsy is the most common form of epilepsy, and current antiepileptic drugs are ineffective in many patients. The endocannabinoid system has been associated with an on-demand protective response to seizures. Blocking endocannabinoid catabolism would elicit antiepileptic effects, devoid of psychotropic effects. We herein report the discovery of selective anandamide catabolic enzyme fatty acid amide hydrolase (FAAH) inhibitors with promising antiepileptic efficacy, starting from a further investigation of our prototypical inhibitor 2a. When tested in two rodent models of epilepsy, 2a reduced the severity of the pilocarpine-induced status epilepticus and the elongation of the hippocampal maximal dentate activation. Notably, 2a did not affect hippocampal dentate gyrus long-term synaptic plasticity. These data prompted our further endeavor aiming at discovering new antiepileptic agents, developing a new set of FAAH inhibitors (3a-m). Biological studies highlighted 3h and 3m as the best performing analogues to be further investigated. In cell-based studies, using a neuroblastoma cell line, 3h and 3m could reduce the oxinflammation state by decreasing DNA-binding activity of NF-kB p65, devoid of cytotoxic effect. Unwanted cardiac effects were excluded for 3h (Langendorff perfused rat heart). Finally, the new analogue 3h reduced the severity of the pilocarpine-induced status epilepticus as observed for 2a.

Circadian Clock and OxInflammation: Functional Crosstalk in Cutaneous Homeostasis.

Circadian rhythms are biological oscillations that occur with an approximately 24 h period and optimize cellular homeostasis and responses to environmental stimuli. A growing collection of data suggests that chronic circadian disruption caused by novel lifestyle risk factors such as shift work, travel across time zones, or irregular sleep-wake cycles has long-term consequences for human health. Among the multiplicity of physiological systems hypothesized to have a role in the onset of pathologies in case of circadian disruption, there are redox-sensitive defensive pathways and inflammatory machinery. Due to its location and barrier physiological role, the skin is a prototypical tissue to study the influence of environmental insults induced OxInflammation disturbance and circadian system alteration. To better investigate the link among outdoor stressors, OxInflammation, and circadian system, we tested the differential responses of keratinocytes clock synchronized or desynchronized, in an in vitro inflammatory model exposed to O3. Being both NRF2 and NF-κB two key redox-sensitive transcription factors involved in cellular redox homeostasis and inflammation, we analyzed their activation and expression in challenged keratinocytes by O3. Our results suggest that a synchronized circadian clock not only facilitates the protective role of NRF2 in terms of a faster and more efficient defensive response against environmental insults but also moderates the cellular damage resulting from a condition of chronic inflammation. Our results bring new insights on the role of circadian clock in regulating the redox-inflammatory crosstalk influenced by O3 and possibly can be extrapolated to other pollutants able to affect the oxinflammatory cellular processes.

Evaluation of oxidative damage and Nrf2 activation by combined pollution exposure in lung epithelial cells.

The lungs are one the main organs exposed to environmental pollutants, such as tropospheric ozone (O3) and particulate matter (PM), which induce lung pathologies through similar mechanisms, resulting in altered redox homeostasis and inflammation. Although numerous studies have investigated the effects of these pollutants in the respiratory tract, there are only a few evidences that have evaluated the combined effects of outdoor stressors, despite the fact that humans are consistently exposed to more pollutants simultaneously. In this study, we wanted to investigate whether exposure to PM and O3 could have an additive, noxious effect in lung epithelial cells by measuring oxidative damage and the activity of redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2) which is a master regulator of cellular antioxidant defenses. First, we measured the cytotoxic effects of O3 and PM individually and in combination. We observed that both pollutants alone increased LDH release 24 h post-exposure. Interestingly, we did observe via TEM that combined exposure to O3 and PM resulted in increased cellular penetration of PM particles. Furthermore, we found that levels of 4-hydroxy-nonenal (4HNE), a marker of oxidative damage, significantly increased 24 h post-exposure, in response to the combined pollutants. In addition, we observed increased levels of Nrf2, in response to the combined pollutants vs. either pollutant, although this effect was not followed by the increase in Nrf2-responsive genes expression HO1, SOD1, GPX, or GR nor enzymatic activity. Despite these observations, our study suggests that O3 exposure facilitate the cellular penetration of the particles leading to an increased oxidative damage, and additive defensive response.

Ethosomes for Coenzyme Q10 Cutaneous Administration: From Design to 3D Skin Tissue Evaluation.

Ethosome represents a smart transdermal vehicle suitable for solubilization and cutaneous application of drugs. Coenzyme Q10 is an endogenous antioxidant whose supplementation can counteract many cutaneous disorders and pathologies. In this respect, the present study describes the production, characterization, and cutaneous protection of phosphatidylcholine based ethosomes as percutaneous delivery systems for coenzyme Q10. CoQ10 entrapment capacity in ethosomes was almost 100%, vesicles showed the typical 'fingerprint' structure, while mean diameters were around 270 nm, undergoing an 8% increase after 3 months from production. An ex-vivo study, conducted by transmission electron microscopy, could detect the uptake of ethosomes in human skin fibroblasts and the passage of the vesicles through 3D reconstituted human epidermis. Immunofluorescence analyses were carried on both on fibroblasts and 3D reconstituted human epidermis treated with ethosomes in the presence of H2O2 as oxidative stress challenger, evaluating 4-hydroxynonenal protein adducts which is as a reliable biomarker for oxidative damage. Notably, the pretreatment with CoQ10 loaded in ethosomes exerted a consistent protective effect against oxidative stress, in both models, fibroblasts and in reconstituted human epidermis respectively.