Simultaneous Production of Antibacterial Protein and Lipopeptides in Bacillus tequilensis, Detected by MALDI-TOF and GC Mass Analyses.

As antibiotic resistance is nowadays one of the important challenges, efforts are crucial for the discovery of novel antibacterial drugs. This study aimed to evaluate antimicrobial/anticancerous activities of halophilic bacilli from the human microbiota. A spore-forming halotolerant bacterium with antibacterial effect against Staphylococcus aureus was isolated from healthy human feces. The antibacterial protein components of the extracted supernatant were identified by SDS-PAGE and zymography. The MALDI-TOF, GC mass, and FTIR analyses were used for peptide and lipopeptide identification, respectively. The stability, toxicity, and anticancerous effects were investigated using MTT and Flow cytometry methods. According to the molecular analysis, the strain was identified as Bacillus tequilensis and showed potential probiotic properties, such as bile and acid resistance, as well as eukaryotic cell uptake. SDS-PAGE and zymography showed that 15 and 10-kDa fragments had antibacterial effects. The MALDI-TOF mass analysis indicated that the 15-kDa fragment was L1 ribosomal protein, which was the first report of the RpL1 in bacilli. GC-mass and FTIR analyses confirmed the lipopeptide nature of the 10-kDa fragment. Both the extracted fractions (precipitation or "P" and chloroform or "C" fractions) were stable at < 100 °C for 10 min, and their antibacterial effects were preserved for more than 6 months. Despite its non-toxicity, the P fraction had anticancer activities against MCF7 cells. The anticancer and antibacterial properties of B. tequilensis, along with its non-toxicity and stability, have made it a potential candidate for studying the beneficial probiotic properties for humans and drug production.

Inhibition of quorum sensing-controlled virulence factors with natural substances and novel protease, obtained from Halobacillus karajensis.

INTRODUCTION: In recent years, a challenge in clinical treatment has developed due to bacterial resistance to antibiotics. One of the new mechanisms against infections is virulence factor inhibition. Many virulence factors are controlled by quorum sensing pathways such as biofilm formation and pyocyanin production. The goal of the present study was to investigate the effect of an obligate halophilic bacterial strain on Pseudomonas aeruginosa and Staphylococcus aureus, due to its halo-tolerant substances and enzymes. METHODS: The effect of Halobacillus karajensis on bacterial growth and production of virulence factors was studied in this work. The obligate halophile cells and supernatant fractions were extracted by the methanol/chloroform method and characterized by Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Gas Chromatography-Mass Spectrometry (GC-MS), and zymography. The effects of these fractions were studied on biofilm formation in P. aeruginosa and S. aureus as well as on pyocyanin production in P. aeruginosa. The effective protein in the fraction was analyzed by the SDS-PAGE method, and all protein fragments were studied for pyocyanin inhibition. RESULTS: The crude supernatant extract, MMS fraction, from H. karajensis was effective for the biofilm reduction in S. aureus (74%) and P. aeruginosa (27%). Two proteases in this fraction, which were recognized by zymography on skim milk, were the probable causes for extracellular polymeric substances (EPS) hydrolysis in the biofilm matrix. Also, halide crystals and branched fatty acids, 12methyl-tetradecanoic acid, in the other fractions decreased the biofilm by 18% in S. aureus. The results showed that a new 25 kD protein, which was obtained from MMS fraction, inhibited pyocyanin production by 60% in P. aeruginosa. The zymogram and bioinformatics studies showed that this protein was a serine alkaline metalloprotease and had an interaction with AHL molecules. CONCLUSION: The inhibitory effects of the non-toxic natural substances and proteases on biofilm formation and pyocyanin production, specifically the 25 kD protease, are novel in this study and make them a good candidate for infected wound healing and inhibiting the virulence factors.

Enhancement of chemoradiation by co-incorporation of gold nanoparticles and cisplatin into alginate hydrogel.

Nonspecificity and high toxicity limit the treatment efficacy and safety of chemoradiation therapy. Effective tumor targeting of anticancer drugs and radiosensitizing agents is highly desirable to amplify the efficacy of this standard cancer therapy approach. To achieve this goal, we exploited the synergy of cisplatin and gold nanoparticles (AuNPs) co-loaded into alginate hydrogel network, forming so-called ACA nanocomplex, and X-ray radiation. Cisplatin is a commonly used anticancer agent, and at the same time, along with AuNPs could function as radiosensitizers to enhance the radiation-induced damages through various pathways. The ACA nanocomplex improved the therapeutic efficiency of standard chemotherapy and yielded 79% growth inhibition in CT26 colon adenocarcinoma tumor after 28 days, which was significantly higher than that of 9% for free cisplatin administration. Moreover, the combination of ACA nanocomplex with 6 MV X-ray dramatically suppressed tumor growth up to 95%, showing 51% enhancement in antitumor activity compared to standard chemoradiation. The nanocomplex developed herein holds the promise to promote the efficiency of standard chemoradiation while maintaining the patient's safety through reducing the clinically administered doses of anticancer drug and X-ray. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2658-2663, 2019.

Nanotechnology in hyperthermia cancer therapy: From fundamental principles to advanced applications.

In this work, we present an in-depth review of recent breakthroughs in nanotechnology for hyperthermia cancer therapy. Conventional hyperthermia methods do not thermally discriminate between the target and the surrounding normal tissues, and this non-selective tissue heating can lead to serious side effects. Nanotechnology is expected to have great potential to revolutionize current hyperthermia methods. To find an appropriate place in cancer treatment, all nanotechnology-based hyperthermia methods and their risks/benefits must be thoroughly understood. In this review paper, we extensively examine and compare four modern nanotechnology-based hyperthermia methods. For each method, the possible physical mechanisms of heat generation and enhancement due to the presence of nanoparticles are explained, and recent in vitro and in vivo studies are reviewed and discussed. Nano-Photo-Thermal Therapy (NPTT) and Nano-Magnetic Hyperthermia (NMH) are reviewed as the two first exciting approaches for targeted hyperthermia. The third novel hyperthermia method, Nano-Radio-Frequency Ablation (NaRFA) is discussed together with the thermal effects of novel nanoparticles in the presence of radiofrequency waves. Finally, Nano-Ultrasound Hyperthermia (NUH) is described as the fourth modern method for cancer hyperthermia.