Antibiofilm and antimicrobial activity of Lactobacillus cell free supernatant against Pseudomonas aeruginosa isolated from burn wounds.

The present study investigated the antimicrobial and anti-biofilm effects of indigenous Lactobacillus probiotic strains on Pseudomonas aeruginosa isolated from burn wound infection in laboratory conditions. The effect of 7 probiotic strains isolated from infant faeces on the pathogenicity factors of P. aeruginosa, including protease, elastase, antibiofilm and antipyocyanin was measured. Also, diffusion methods in the well and micro broth dilution were used to evaluate the antimicrobial activity of probiotics. All tests were performed in triplicate. A negative control and a positive control were used for each test. SPSS version 22 software was used for statistical analysis, and a p < 0.05 was considered statistically significant. A total of 30 clinical isolates of P. aeruginosa were isolated. The elastolytic activity of P. aeruginosa isolates decreased after adding Cell free supernatant (CFS) of each Lactobacillus. L1, L4, L5, and L6 strains had a 100% inhibitory effect on pathogen isolates. L3 and L7 strains had the lowest inhibitory effect. The inhibitory effect of CFS extracted from lactobacilli on protease production by P. aeruginosa. L1, L4, L5, and L6 strains had an inhibitory effect on all tested isolates. L2, L3, and L7 strains had a less inhibitory effect. L4 strain had the highest inhibitory effect on pyocyanin production by P. aeruginosa (50%), followed by L5 (43.3%), L1 (40%), and L6 (23.3%) strains. L3 and L7 strains had no inhibitory effect on the pyocyanin production of P. aeruginosa isolates. It was found that the CFS of 4 isolates (L1, L4, L5, and L6) was the most active extract and had a 100% inhibitory effect against biofilm formation of all P. aeruginosa strains. The L3 strain had the least inhibitory effect against the biofilm formation of pathogens. Overall, this study showed that probiotics could be promising alternatives to combat the pathogenicity of P. aeruginosa in burn wounds.

Gold nanostructure-mediated delivery of anticancer agents: Biomedical applications, reversing drug resistance, and stimuli-responsive nanocarriers.

The application of nanoarchitectures in cancer therapy seems to be beneficial for the delivery of antitumor drugs. In recent years, attempts have been made to reverse drug resistance, one of the factors threatening the lives of cancer patients worldwide. Gold nanoparticles (GNPs) are metal nanostructures with a variety of advantageous properties, such as tunable size and shape, continuous release of chemicals, and simple surface modification. This review focuses on the application of GNPs for the delivery of chemotherapy agents in cancer therapy. Utilizing GNPs results in targeted delivery and increased intracellular accumulation. Besides, GNPs can provide a platform for the co-delivery of anticancer agents and genetic tools with chemotherapeutic compounds to exert a synergistic impact. Furthermore, GNPs can promote oxidative damage and apoptosis by triggering chemosensitivity. Due to their capacity for providing photothermal therapy, GNPs can enhance the cytotoxicity of chemotherapeutic agents against tumor cells. The pH-, redox-, and light-responsive GNPs are beneficial for drug release at the tumor site. For the selective targeting of cancer cells, surface modification of GNPs with ligands has been performed. In addition to improving cytotoxicity, GNPs can prevent the development of drug resistance in tumor cells by facilitating prolonged release and loading low concentrations of chemotherapeutics while maintaining their high antitumor activity. As described in this study, the clinical use of chemotherapeutic drug-loaded GNPs is contingent on enhancing their biocompatibility.