No abstract

No abstract

In the current study, niosome‐encapsulated tobramycin based on Span 60 and Tween 60 was synthesized and its biological efficacies including anti‐bacterial, anti‐efflux, and anti‐biofilm activities were investigated against multidrug resistant (MDR) clinical strains of Pseudomonas aeruginosa. The niosomal formulations were characterized using scanning electron microscopy, transmission electron microscopy, and dynamic light scattering measurement. The encapsulation efficiency was found to be 69.54% ±; 0.67. The prepared niosomal formulations had a high storage stability to 60 days with small changes in size and drug entrapment, which indicates that it is a suitable candidate for pharmaceutical applications. The results of biological study showed the anti‐bacterial activity via reduction of antibiotic resistance, enhanced anti‐efflux and anti‐biofilm activities by more folds in comparison to free tobramycin. In addition, niosome encapsulated tobramycin down‐regulated the MexAB‐OprM efflux genes, pslA and pelA biofilm related genes in MDR P. aeruginosa strains. The anti‐proliferative activity of formulation was evaluated against HEK293 cell lines, which exhibited negligible cytotoxicity against HEK293 cells. The finding of our study shows that encapsulation of tobramycin in niosome enhanced the antibacterial activity and reduced antibiotic resistance in MDR strains of P. aeruginosa comparing to free tobramycin and it can be considered as a favorable drug delivery system.

Silver nanoparticles (AgNPs) were synthesized using Artemisia oliveriana extract, and their physicochemical characteristics were studied. The antioxidant and antimicrobial activities of the AgNPs, as well as their anticancer effects on the lung cancer cell line (A549), using 1,1-diphenyl-2-picrylhydrazyl (DPPH), MIC and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) techniques respectively demonstrated that the synthesized AgNPs mainly affected the gram-positive bacteria rather than the gram-negative bacteria, and exhibited significant cellular toxicity on the A549 cell line. Further, the cellular uptake of the AgNPs results indicated that the AgNPs accumulated within the cell. Moreover, their impact on the expression of apoptotic genes including Bax, Bcl-2, caspase-3 (CASP3), caspase-9 (CASP9) and miR-192 using real-time PCR demonstrated substantial increase in the expression of all mentioned genes (p<.001). Finally, the apoptotic effects of the AgNPs through DNA fragmentation test, flow cytometry and cell cycle analysis indicated the induction of apoptosis in the A549 cell line. The results revealed that the AgNPs synthesized using A. oliveriana extract have potential biological applications.