E-cigarette aerosol induced cytotoxicity, DNA damages and late apoptosis in dynamically exposed A549 cells.

In this study, the acute toxicological impacts associated with electronic cigarettes consumption were determined using a novel dynamic exposure methodology. The methodology was deployed to test various e-cigarette generated aerosols in A549 cell cultures. The e-liquid chemical profiling was achieved using GC-MS analysis while toxicity of diluted e-liquids aerosols was reported using numerous cytotoxicity assays. The presented findings pointed to acute aerosol exposure (thirty puffs at 40 W of power and higher) inducing significant cytotoxic, genotoxic, and apoptotic induction in exposed cells. These findings highlighted the significant risks posed by e-cigarette usage. The proposed methodology proved to be a useful tool for future screening of e-liquids generated aerosols toxicity. Future research is needed to establish the chronic toxicity resulting from long-term e-cigarette consumption.

Evaluation of waterpipe smoke toxicity in C57BL/6 mice model.

Waterpipe smoking is a popular pastime worldwide with statistics pointing to an alarming increase in consumption. In the current paper, the evaluation of sub-chronic waterpipe smoke exposure was undertaken using C57BL/6 female mice using a dynamic exposure setting to emulate smoke exposure. Mice were daily subjected to either one (single exposure, SE) or two sessions (double exposure, DE) of waterpipe-generated smoke (two-apple flavor) for a period of two months. Although lungs histopathological examination pointed to a minor inflammation in smoke-exposed mice compared to control air-exposed (CON) group, the lung weights of the waterpipe-exposed mice were significantly higher (+72% in SE and +39% in DE) (p < 0.01) when compared to CON group. Moreover, changes in the protein expression of several proteins such as iNOS and JNK were noted in the lungs of smoke-exposed mice. However, no changes in p38 and EGFR protein levels were noted between the three groups of mice. Our results mainly showed a significant increase in urea serum levels (+28%) in SE mice along with renal pathological damage in both SE and DE mice compared to CON. Additionally, severe significant DNA damages (p < 0.05) were reported in the lungs, kidneys, bone marrow and liver of waterpipe-exposed animals, using MTS and COMET assays. These findings highlighted the significant risks posed by sub-chronic waterpipe smoke exposure in the selected animal model and the pressing need for future better management of waterpipe indoor consumption.

Characterization and cytotoxicity assessment of nargile smoke using dynamic exposure.

Objectives: Nargile (waterpipe) smoking has gained popularity in the Middle East and throughout the world. In this research, a new dynamic methodology was conceived. This methodology was deployed for direct in vitro assessment of cytotoxicity, genotoxicity, and apoptotic potential of smoke generated from a single nargile session. Materials and methods: A549 cells were deployed in a designed system to assess the cytotoxicity of generated smoke. The smoke was characterized using Gas chromatography-mass spectrometry (GC-MS) profiling for major organic compounds, whereas the remaining chemical and physical parameters were tabulated from published data. The cytoxicity of smoke generated from five commercial flavored tobacco products was assessed using the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2-H-tetrazolium) (MTS) assay. The genotoxicity was also measured using the comet assay, while apopoptosis was evaluated using Annexin V/propidium iodide staining.Results: The data indicated acute cytotoxicity emanating from smoke products in all tested tobacco flavors. Significant loss of viability and mitochondrial activity was observed 40 min post smoke exposure (Double-Apple flavored), while DNA damage onset was reported as early as 20 min of exposure. Microscopical analysis showed a systematic increase in cell rounding post exposure indicating cellular loss of adhesion and potential membrane damages. Finally, the Annexin V/propidium iodide cellular staining showed signs of late apoptosis or necrosis in exposed cells. Conclusions: The presented data clearly indicated significant in vitro cytotoxicity, genotoxicity and apoptosis/necrosis associated with a 60-min single session of nargile smoking.

Spontaneous formation of fluorescent nanofibers and reticulated solid from berberine palmitate: a new example of aggregation-induced emission enhancement in organic ion pairs.

The salt formed between the large aromatic berberine cation and the long-chain palmitate anion was synthesized and used to prepare aqueous suspensions of particles owing to a solvent-exchange method. Under these conditions, elongated particles were readily obtained. They were studied by transmission microscopy with polarized light, as well as by fluorescence and electron microscopy. They were shown to be probably crystallized nanofibers, which were stable in suspension. Unexpectedly, upon filtration and drying, these fibers evolved to give a reticulated solid. The fluorescence properties of the compound were analyzed in solution, in aqueous suspension and in the powder crystalline state. Interestingly, berberine palmitate is virtually not fluorescent in aqueous solution because of the quenching effect of water, but transition to the solid state was accompanied by a strong increase in fluorescence intensity. This phenomenon was explained by the original molecular arrangement in the solid state. Actually, in the crystal, the anions form a distinct layer, which limits parallel-stacking of the fluorescent cations. Moreover, the berberine cations are protected from the access of water molecules, and so no quenching effect can take place. This example confirms that the newly introduced concept of ion-pair aggregation-induced fluorescence enhancement can be extended to a variety of structures. It also shows the interest of ion pairs for preparing fluorescent nanofibers and reticulated solids using a solvent-exchange method that is particularly easy to implement.

A facile route for the preparation of nanoparticles of the spin-crossover complex [Fe(Htrz)2(trz)](BF4) in xerogel transparent composite films.

Films and monoliths containing the spin crossover complex [Fe(Htrz)(2)(trz)](BF(4)) (trz = 1,2,4-triazole) as nanoparticles have been obtained. The dispersion and consecutive inclusion of the Fe complex in a silica matrix prepared from tetramethoxysilane or tetraethoxysilane afford monoliths or films with a violet colour at room temperature, which turns white above 380 K. This change of colour is reversible. This thermochromic behaviour has been characterized by measuring the magnetic properties together with thermogravimetric studies and Raman spectroscopy, the result of which all demonstrate that both films and monoliths undergo a spin crossover. Microscopy studies confirm the occurrence of the Fe complex as nanoparticles, in both the monoliths and the films. The facile synthesis of these materials as nanoparticles in transparent films should open the possibility of the synthesis of high quality films.