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Background: Given the global problem of antibiotic resistance among pathogens, researchers are looking for appropriate treatment alternatives to eliminate infections. Application of probiotics and their products can be a practical solution. This study aimed to investigate the inhibitory effect of cell-free supernatant (CFS) of probiotics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Methods: The effect of CFS of eight strains of probiotics against E. coli and S. aureus was evaluated by well diffusion method. The agent with the highest inhibition diameter was selected to investigate other antibacterial properties. They included minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and timed kill effect. Surface electron micrographs were taken to compare the treated versus untreated bacteria with CFS of Lactobacillus acidophilus (SLA) LAFTI-L10 DSL. Finally, the percent viability of the Hu02 cells was investigated after 24, 48 or 72 hours of incubation with SLA at various concentrations. Results: Among the tested strains, SLA showed the highest inhibitory diameter against E. coli and S. aureus (P=0.005). Also, the MIC of SLA was equal to those of E. coli and S. aureus (12.5 mg/mL) but was different in their MBC. Almost 100% of bacteria removed after exposure to SLA (20 min.). The results of log CFU/mL demonstrated that SLA had bactericidal effect against S. aureus and E. coli. The toxicity assays showed that the percent viability of the Hu02 cells was 31.71 to 81.09 after 24, 48 or 72 hours exposure. Conclusions: Our results suggest that SLA can be a suitable, effective and safe alternative to antibiotics. [ABSTRACT FROM AUTHOR]

Flaxseed oil as a natural ingredient has many health benefits due to the rich contents of omega‐3 fatty acids. However, its use in food formulations is limited because of low aqueous solubility, easy oxidation owing to the unsaturated nature of the fatty acids such as omega‐3. The aim of this study was to prepare a stable nanoemulsion containing flaxseed oil and investigate the fortification of yogurt with this nanoemulsion compared with fortification with bulk flaxseed oil. The nanoemulsion of flaxseed oil‐in‐water was obtained by low‐energy emulsification method. Optimized nanoemulsion contains 3% (w/w) flaxseed vegetable oil, 36% (w/w) surfactant, 10% (w/w) co‐surfactant, and 51% (w/w) deionized water as a continuous phase. The result of transmission electron microscopy (TEM) showed that the optimal size was about 60 nm, which was stayed stable for 11 months. The results of gas chromatography (GC) indicated that the amount of omega‐3 in nanoemulsion containing flaxseed oil was 27.3% and 19.8% after 7 days and 11 months, respectively. The turbidity results indicated the transparency of nanoemulsion after 11 months as well. The results of centrifuge experiments and thermal stress cycles exhibited that the optimized nanoemulsion was physically stable without any sign of creaming, phase separation, and cracking. In addition, pH and acidity of the yogurt fortified with nanoemulsion containing flaxseed oil were 4.22 and 1.41 wt%, respectively. In conclusion, fortifying yogurt with the nanoemulsion containing flaxseed oil can be considered as a solution to increase solubility, bioavailability, and protection of omega‐3. [ABSTRACT FROM AUTHOR]

Purpose: The size of polymeric nanoparticles is considered as an effective factor in cancer therapy due to enterance into tumor tissue via the EPR effect. The purpose of this work was to investigate the effective parameters on poly(lactic-co-glycolic acid)-paclitaxel (PLGA - PTX) nanoparticles size. Methods: We prepared PLGA-PTX nanoparticles via single emulsion and precipitation methods with variable paremeters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration. Results: PLGA-PTX nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results exhibited that the diameter of nanoparticles enhanced with increasing drug, polymer and PVA concentrations whereas organic to aqueous phase volume ratio and sonication time required to the optimization for a given size. Conclusion: The precipitation method provides smaller nanoparticles compared to emulsion one. Variable parameters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration affect diameter of nanoparticles. [ABSTRACT FROM AUTHOR]

The purpose of this work was to fabricate an electrochemical DNA biosensor for detecting hepatitis B virus. Gold nanorods (GNRs), which are known for their conductivity, were used to increase surface area and consequently increase the immobilization of single-stranded DNA (ss-DNA) on the modified gold electrode. The GNRs were characterized via transmission electron microscopy. The morphology of the gold electrode before and after modification with GNRs was characterized by scanning electron microscopy. Atomic-force microscopy was used to evaluate the morphology of the GNR electrode surface before and after interaction with ss-DNA. Cyclic voltammetry was used to monitor DNA immobilization and hybridization, using [Co(phen)] as an electrochemical indicator. The target DNA sequences were quantified at a linear range from 1.0 × 10 to 10.0 × 10 mol L, with a detection limit of 2.0 × 10 mol L by 3 σ. The biosensor had good specificity for distinguishing complementary DNA in the presence of non-complementary and mismatched DNA sequences. [ABSTRACT FROM AUTHOR]