35 research outputs found

    In vitro and in vivo anticancer effect of pH-responsive paclitaxel-loaded niosomes

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    In this study, paclitaxel (PTX)-loaded pH-responsive niosomes modified with ergosterol were developed. This new formulation was characterized in terms of size, morphology, encapsulation efficiency (EE), and in vitro release at pH 5.2 and 7.4. The in vitro efficacy of free PTX and niosome/PTX was assessed using MCF7, Hela, and HUVEC cell lines. In order to evaluate the in vivo efficacy of niosomal PTX in rats as compared to free PTX, the animals were intraperitoneally administered with 2.5 mg/kg and 5 mg/kg niosomal PTX for two weeks. Results showed that the pH-responsive niosomes had a nanometric size, spherical morphology, 77% EE, and pH-responsive release in pH 5.2 and 7.4. Compared with free PTX, we found markedly lower IC50s when cancer cells were treated for 48 h with niosomal PTX, which also showed high efficacy against human cancers derived from cervix and breast tumors. Moreover, niosomal PTX induced evident morphological changes in these cell lines. In vivo administration of free PTX at the dose of 2.5 mg/kg significantly increased serum biochemical parameters and liver lipid peroxidation in rats compared to the control rats. The situation was different when niosomal PTX was administered to the rats: the 5 mg/kg dosage of niosomal PTX significantly increased serum biochemical parameters, but the group treated with the 2.5 mg/kg dose of niosomal PTX showed fewer toxic effects than the group treated with free PTX at the same dosage. Overall, our results provide proof of concept for encapsulating PTX in niosomal formulation to enhance its therapeutic efficacy. [Figure not available: see fulltext.

    Enzyme production from food wastes using a biorefinery concept

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    According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes

    Analysis of virulence genes and molecular typing of Listeria monocytogenes isolates from human, food, and livestock from 2008 to 2016 in Iran

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    The frequency of Listeria monocytogenes isolates collected from a total of 1150 samples including food (n = 300), livestock (n = 50), and human clinical (n = 800) was evaluated during 2008�2016. Antimicrobial resistance patterns, virulence factors, and molecular characteristics of these isolates were analyzed using disk diffusion method, sequencing, serotyping, and pulsed-field gel electrophoresis (PFGE). The analysis of 44 L. monocytogenes isolates showed that 72.7 (32 of 44) of all the isolates belonged to Serotype 1/2c, and 15.9 (7 of 44) belonged to Serotype 3c. All 44 isolates were resistant to one or more antimicrobial agents with the most frequent resistance to penicillin (75) and tetracycline (47.7). Of the 44 L. monocytogenes strains, 100, 69.2, and 62.5 of livestock, human, and food strains were resistant to penicillin, respectively. Using pulsed-field gel electrophoresis (PFGE) technique, the isolates� genetic diversity was determined, and 28 PFGE patterns with 8 common (CT) and 20 single types (ST) were identified. This study highlights the high prevalence of Serotype 1/2c in clinical and livestock samples, while different serotypes were observed in food samples. The presence of rare serotypes such as 4c, belonging to the Lineage III, as well as 4e and 1/2c which are infrequent in Iran indicates that paying attention to uncommon serotypes, especially 1/2c, during the listeriosis outbreaks is necessary. © 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature

    Comprehensive analysis of Enterococcus strains isolated from human microbiome and evaluation of their benefits for digestive system

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    Background: Some studies have highlighted a mutualistic relationship between human and Enterococcus spp.; however, other surveys have showed only a commensal connection. This study aimed to clearly answer this question that whether or not Enterococci strains have a beneficial potential for the human GI tract? Methods: The fecal samples were collected from 1000 healthy volunteers. Inhibitory potency of these bacteria was evaluated on three intestinal pathogens using phenotypic agar spot assay and genotypic PCR method. After typing bacteria by PFGE, the probiotic supplemented tests were used for evaluating Enterococci beneficial potential. Results: Out of 1000 fecal isolated Enterococci strains, 91 isolates were identified as E. faecium; entA (88.6) and entB (26.8) were present almost in all of the isolates. Also, 100 of the E. faecium isolates were active against EAEC and Shigella dysenteriae (zone �10 mm); however, these E. faecium isolates weren't effective against EPEC. Moreover, it was found that 9 out of 91 E. faecium isolates had >50 viability in bile salts and acid stress assays, and only 4 of these 9 acid-bile resistant isolates were able to adhere to HT-29 cell line. Conclusions: To sum up, almost 4 of human isolated Enterococcus spp. were shown to have a mutualistic behavior with an impressive probiotic potential. It is believed that in the future, these mutualistic Enterococci could be replaced by commensal ones in all people by taking probiotic supplements containing Enterococci. © 202

    Novel vaccine candidates against Mycobacterium tuberculosis

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    Tuberculosis (TB) is now among the top ten causes of mortality worldwide being resulted in 1.7 million deaths including 0.4 million among people with HIV in 2016. The Bacille Calmette-Guerin (BCG) is the only available TB vaccine which fails to provide consistent protection against pulmonary TB in adults and adolescents despite being efficacious at protecting infants and young children from the most severe, often deadly forms of TB disease. To achieve the goal of global TB elimination by 2050 we will need new interventions including more improved vaccines that are effective in adult individuals who have not been infected with Mycobacterium tuberculosis as well as latently infected or immunocompromised subjects. In recent decades, multiple new vaccine candidates including whole cell vaccines, adjuvanted proteins, and vectored subunit vaccines have entered into the clinical trials. These new TB vaccines are hoped to provide encouraging safety and immunogenicity under various conditions including prevention of TB disease in adolescents and adults, as BCG replacement/boosters, or as therapeutic vaccines to reduce the duration of TB therapy. In this review, we will discuss the status of novel TB vaccine candidates currently under development in preclinical or clinical phases. © 2018 Elsevier B.V

    Asymmetric Hydrogenation of α‑Amino Ester Probed by FTIR Spectroscopy

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    Asymmetric hydrogenation reaction of dehydro-α-amino acid (i.e., α-amino ester) over cinchonidine (CD) modified Pd catalyst has been studied by an array of in situ infrared spectroscopic methods, including transmission, diffuse reflectance (DR), and attenuated total reflectance (ATR). Transmission FTIR spectra probed the hydrogenation reaction process, revealed OH–O and NH–N hydrogen bonding interactions between the adsorbed CD and during the reaction. DR and ATR spectra of the hydrogenation reaction under different conditions, which are consistent with but slightly different from the transmission spectra, evidenced the successful hydrogenation of the compound. The incorporation of DR and microfluidics flow-through design allowed us to investigate the adsorption of CD on the Pd surface efficiently. The results revealed that the N-bonded CD on Pd surface in a tilted configuration had increased abundance on the Pd surface with high coverage. These valuable insights provided an image of the reaction pathway to the prochiral structure (precursor state)

    The expression of type II TA system genes following exposure to the sub-inhibitory concentration of gentamicin and acid stress in Brucella spp

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    Background: Brucellosis is one of the most common diseases that afflicts both humans and animals. Bacteria react to stress conditions using different mechanisms one of which is Toxin-Antitoxin (TA) systems. It is believed that the Toxin-Antitoxin (TA) systems have a key role in the chronicity of the disease. This study investigated the expression of TA system genes under acid and antibiotic stresses in Brucella spp. Methods: Fifty Brucella isolates (17 isolated from animals and 31 isolated from human specimens, and two standard strains) were analyzed using PCR (using two pairs of primers). Then, to determine the effects of subMIC of gentamicin on bacterial survival and growth, colony forming unit was quantitated and turbidity was assessed following the treatment of Brucella spp, with 1/2 MIC of gentamicin at different time intervals. Furthermore, the colony forming unit of Brucella spp, was assessed under acid stress (pH = 5.5) compared to the control (pH = 7.6). Moreover, the expression of TA system genes in Brucella spp, was evaluated 1 h after treatment using qRT-PCR method. Results: A total of 50 isolates, including 41 (82) Brucella melitensis and 7 (14) Brucella abortus with two standard strains Brucella melitensis (16 M) and Brucella abortus (B19) were investigated. Our results revealed the reduced growth of Brucella spp. in the presence of sub-MIC of gentamicin compared to the control. Furthermore, according to the results of qRT-PCR assay, gentamicin could increase the expression of TA system genes. Also, results of qRT-PCR showed that under acid stress, the expression of TA system gene COGT/COGAT decreased compared to the control. Conclusion: Although the exact role of the TA systems in response to stress is still unclear, our study provided information on the effect of the type II TA systems under the acid and antibiotic stress conditions. However, further studies are still required

    Asymmetric Hydrogenation of α‑Amino Ester Probed by FTIR Spectroscopy

    No full text
    Asymmetric hydrogenation reaction of dehydro-α-amino acid (i.e., α-amino ester) over cinchonidine (CD) modified Pd catalyst has been studied by an array of in situ infrared spectroscopic methods, including transmission, diffuse reflectance (DR), and attenuated total reflectance (ATR). Transmission FTIR spectra probed the hydrogenation reaction process, revealed OH–O and NH–N hydrogen bonding interactions between the adsorbed CD and during the reaction. DR and ATR spectra of the hydrogenation reaction under different conditions, which are consistent with but slightly different from the transmission spectra, evidenced the successful hydrogenation of the compound. The incorporation of DR and microfluidics flow-through design allowed us to investigate the adsorption of CD on the Pd surface efficiently. The results revealed that the N-bonded CD on Pd surface in a tilted configuration had increased abundance on the Pd surface with high coverage. These valuable insights provided an image of the reaction pathway to the prochiral structure (precursor state)
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