Assessment of nicotine for second hand smoke exposure in some public places in Romania by UPLC-MS

BACKGROUND: Air nicotine monitoring is a well-known procedure for estimation of exposure to second hand smoke. Few research studies were realized in Romania to evaluate environmental tobacco smoke (ETS) exposure of humans in different public places. The levels of airborne nicotine from environmental tobacco smoke and urinary cotinine and nicotine levels of some subjects were analyzed. In order to better implement/enforce the European legislation regarding the interdiction of smoking in the public places the national authorities need a rapid and reliable analytical method to quickly asses the state of the pollution with cigarette smoke of these populated areas. RESULTS: The nicotine concentration in the air from different types of public buildings was determined. The median concentration of nicotine in the air from 32 pubs where the smoking was allowed was 590 ng · L(-1), comparing with the pubs where the smoking was not permitted (22 locations) where the median concentration of nicotine was only 32 ng · L(-1). Similarly, the median concentration of nicotine in restaurants where the smoking was allowed (23 locations) was 510 ng · L(-1), in comparison with the restaurants where the smoking was prohibited (11 places) where the median value was 19 ng · L(-1). The lowest concentrations of nicotine were found in high schools (8 locations, median concentration 7.4 ng · L(-1)), universities (5 locations, 23 ng · L(-1)) and hospitals (6 locations, 16 ng · L(-1)). CONCLUSIONS: The method was validated and gave good linearity, precision, accuracy and limit of detection. The buildings included hospitals, high schools, universities, pubs and restaurants. The presence of air nicotine was recorded in all buildings studied. The highest median levels of air nicotine were found in pubs and restaurants. The presence of air nicotine in indoor public buildings indicates weak implementation of the smoke free law in Romania

Determination of methylparaben from cosmetic products by ultra performance liquid chromatography

A new method for the determination of methylparaben by ultra-performance liquid chromatography (UPLC) was developed. Methylparaben is often used as preservative, alone or in combination with other parabens, being added to cosmetic products, pharmaceutical products and foods to avoid microbial contamination. Due to its widespread use and potential risk to human health, assessing human exposure to this compound is of interest. A good determination and quantification of methylparaben was developed with a gradient elution using a mixture of methanol and water (60:40, v/v) within 1.455 min. Under optimized conditions, the linear working range extends over two orders of magnitude with relative standard deviations of intra- and inter-day precision below 2.3 %, and a detection limit of 0.02 ng μL-1 for methylparaben. The proposed method was successfully applied to the assay of methylparaben in cosmetic products with minimal sample preparation

Non-conventional expression of recombinant chitinase A originating from Bacillus licheniformis DSM8785, in Saccharomyces cerevisiae INVSc1: Scientific paper

Chitinases are glycosyl hydrolases, that cleave the β-1,4 linkage between N-acetyl glucosamines present in chitin chains. Chitin is the second most abundant polysaccharide on Earth after cellulose, and it is produced in the exoskeleton of crustaceans and insects, and in some parts of the cell walls of fungi. Enzymatic development and the extraction of superior derivatives from chitin wastes – such as chitooligosaccharides with vast importance in the medi­cal and biofuels industry – lead to the necessity of creating chitinases using dif­ferent strains of organisms. In this paper, the chiA gene from the Bacillus lich­eniformis DSM8785 encoding chitinase A (ChiA) with C-terminal hexahis­tid­ine tag was cloned and expressed in the extracellular expression system pYES2 from Saccharomyces cerevisiae INVSc1 as a hyperglycosylated enzyme. The production of recombinant ChiA was successfully confirmed by dot blotting, using anti-His antibodies. The optimal time of expression was identified to be 24 h when galactose was added only at the beginning of fermentation, the chit­in­ase activity starting to decrease after this threshold. Nevertheless, in another experiment, when galactose was added every 24 h for 72 h, the expression con­tinued for the entire period. The purified enzyme was detected, using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE), as a het­ero­geneous diffuse band between 80 and 180 kDa. The molecular mass of the same ChiA enzyme expressed in Pichia pastoris KM71H and Escherichia coli BL21 (DE3) was compared using SDS-PAGE with ChiA expressed in S. cere­visiae INVSc1. The activity of ChiA was determined using the fluorogenic substrate, 4-methylumbelliferyl β-d-N,N,N-triacetylchitotrioside (4MUTC). Using a bioinformatics simulation, the number of the glycolsylation sites of the ChiA gene sequence and the proximity of these sites to the alpha factor sequ­ence were hypothesized to be a possible reason for which ChiA enzyme was internally expressed

Understanding the Factors Influencing Chitosan-Based Nanoparticles-Protein Corona Interaction and Drug Delivery Applications

Chitosan is a polymer that is extensively used to prepare nanoparticles (NPs) with tailored properties for applications in many fields of human activities. Among them, targeted drug delivery, especially when cancer therapy is the main interest, is a major application of chitosan-based NPs. Due to its positive charges, chitosan is used to produce the core of the NPs or to cover NPs made from other types of polymers, both strategies aiming to protect the carried drug until NPs reach the target sites and to facilitate the uptake and drug delivery into these cells. A major challenge in the design of these chitosan-based NPs is the formation of a protein corona (PC) upon contact with biological fluids. The composition of the PC can, to some extent, be modulated depending on the size, shape, electrical charge and hydrophobic/hydrophilic characteristics of the NPs. According to the composition of the biological fluids that have to be crossed during the journey of the drug-loaded NPs towards the target cells, the surface of these particles can be changed by covering their core with various types of polymers or with functionalized polymers carrying some special molecules, that will preferentially adsorb some proteins in their PC. The PC’s composition may change by continuous processes of adsorption and desorption, depending on the affinity of these proteins for the chemical structure of the surface of NPs. Beside these, in designing the targeted drug delivery NPs one can take into account their toxicity, initiation of an immune response, participation (enhancement or inhibition) in certain metabolic pathways or chemical processes like reactive oxygen species, type of endocytosis of target cells, and many others. There are cases in which these processes seem to require antagonistic properties of nanoparticles. Products that show good behavior in cell cultures may lead to poor in vivo results, when the composition of the formed PC is totally different. This paper reviews the physico-chemical properties, cellular uptake and drug delivery applications of chitosan-based nanoparticles, specifying the factors that contribute to the success of the targeted drug delivery. Furthermore, we highlight the role of the protein corona formed around the NP in its intercellular fate

A Meta-Analysis on Randomised Controlled Clinical Trials Evaluating the Effect of the Dietary Supplement Chitosan on Weight Loss, Lipid Parameters and Blood Pressure

Background and objectives: Erratic results have been published concerning the influence of the dietary supplement chitosan used as a complementary remedy to decrease the body weight of overweight and obese people. The published articles mention as secondary possible benefits of usage of chitosan the improvement of blood pressure and serum lipids status. We performed a meta-analysis evaluating body weight, body mass index, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure among overweight and obese patients. Materials and Methods: Searching MEDLINE, Cochrane up to December 2017 on clinical trials that have assessed the influence of chitosan used as a dietary supplement on overweight and obese patients. An additional study was identified in the References section of another meta-analysis. A total of 14 randomised control trials (RCT) were used to assess the effect on body weight, serum lipids and blood pressure. Results: The usage of chitosan as a dietary supplement up to 52 weeks seems to slightly reduce the body weight (−1.01 kg, 95% CI: −1.67 to −0.34). Considering the other parameters studied, the most significant improvement was observed in systolic and diastolic blood pressure: −2.68 mm Hg (95% CI: −4.19 to −1.18) and −2.14 mm Hg (95% CI: −4.14 to −0.14) in favour of chitosan versus a placebo. Conclusions: Based on the meta-analysis realized with 14 RCT we concluded that the usage of chitosan as a dietary supplement can lead to a slight short- and medium-term effect on weight loss and to the improvement of serum lipid profile and cardiovascular factors

Electrochemical Sensing and Assessment of Parabens in Hydro- Alcoholic Solutions and Water Using a Boron-Doped Diamond Electrode

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