Green synthesis of silver and gold-doped zinc oxide nanocomposite with propolis extract for enhanced anticancer activity.

Metal and metal oxide nanocomposites have unique properties and are promising for antibacterial and anticancer applications. In this work, we aimed to highlight the relationship between the biosynthesis ways of silver and gold-doped zinc oxide nanocomposites and their functions as anticancer on cell lines (MCF-7 and HepG2). The propolis was used to biosynthesize four different nanoparticles with the same components, including zinc, gold and silver. The nanocomposites were characterized using various techniques, including ultraviolet-visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray analysis (EDX) and cytotoxicity assays. The result of this study showed that formed nanocomposites have a similar level of Zn, Au, and Ag, ranging from 23-34%, 2-6%, and 2-3%, respectively. In addition, adding the components simultaneously produces the fastest color change, and the fabricated nanoparticles have spherical shapes with different layers. In addition, the prepared nanoparticles influenced the cell viability of the cancer cell lines, with the most effective one when Zn, Au, and Ag were added spontaneously to form a nanocomposite called (All) with IC50 of 24.5 µg/mL for MCF7 cells and 29.1 µg/mL for HepG2 cells. Thus, the study illustrates that the preparation of nanocomposite generated through green synthesis with different methods significantly affects the structure and function and may improve the synthesis of nanocomposite to be developed into an efficacious therapeutic agent for cancers. In addition, this study opens the door toward a novel track in the field of nanocomposites as it links the synthesis with structure and function. Further anti-cancer properties, as well as animal testing are needed for those nanocomposites.

Characterization, antibacterial, and cytotoxic activities of silver nanoparticles using the whole biofilm layer as a macromolecule in biosynthesis.

Recently, multi-drug resistant (MDR) bacteria are responsible for a large number of infectious diseases that can be life-threatening. Globally, new approaches are targeted to solve this essential issue. This study aims to discover novel antibiotic alternatives by using the whole components of the biofilm layer as a macromolecule to synthesize silver nanoparticles (AgNPs) as a promising agent against MDR. In particular, the biosynthesized biofilm-AgNPs were characterized using UV-Vis spectroscopy, electron microscopes, Energy Dispersive X-ray (EDX), zeta sizer and potential while their effect on bacterial strains and normal cell lines was identified. Accordingly, biofilm-AgNPs have a lavender-colored solution, spherical shape, with a size range of 20-60 nm. Notably, they have inhibitory effects when used on various bacterial strains with concentrations ranging between 12.5 and 25 µg/mL. In addition, they have an effective synergistic effect when combined with phage ZCSE9 to inhibit and kill Salmonella enterica with a concentration of 3.1 µg/mL. In conclusion, this work presents a novel biosynthesis preparation of AgNPs using biofilm for antibacterial purposes to reduce the possible toxicity by reducing the MICs using phage ZCSE9.

The Lytic Activity of Bacteriophage ZCSE9 against Salmonella enterica and Its Synergistic Effects with Kanamycin.

Salmonella, the causative agent of several diseases in humans and animals, including salmonellosis, septicemia, typhoid fever, and fowl typhoid, poses a serious threat to global public health and food safety. Globally, reports of therapeutic failures are increasing because of the increase in bacterial antibiotic resistance. Thus, this work highlights the combined phage-antibiotic therapy as a promising approach to combating bacterial resistance. In this manner, the phage ZCSE9 was isolated, and the morphology, host infectivity, killing curve, combination with kanamycin, and genome analysis of this phage were all examined. Morphologically, phage ZCSE9 is a siphovirus with a relatively broad host range. In addition, the phage can tolerate high temperatures until 80 °C with one log reduction and a basic environment (pH 11) without a significant decline. Furthermore, the phage prevents bacterial growth in the planktonic state, according to the results of the time-killing curve. Moreover, using the phage at MOI 0.1 with kanamycin against five different Salmonella serotypes reduces the required antibiotics to inhibit the growth of the bacteria. Comparative genomics and phylogenetic analysis suggested that phage ZCSE9, along with its close relatives Salmonella phages vB_SenS_AG11 and wksl3, belongs to the genus Jerseyvirus. In conclusion, phage ZCSE9 and kanamycin form a robust heterologous antibacterial combination that enhances the effectiveness of a phage-only approach for combating Salmonella.

The synergistic effect of using bacteriophages and chitosan nanoparticles against pathogenic bacteria as a novel therapeutic approach.

Public health and environmental security are seriously at risk due to the growing contamination of pathogenic microorganisms. Therefore, effective antimicrobials are urgently needed. In our study, the antimicrobial effects of three types of nanoparticles were investigated with phage. The biosynthesis of nanoparticles was confirmed based on the color change and shapes, which tended to be mono-dispersed with a spherical shape with a size range of 20-35 nm for Ag-CS-NPs; 15-30 nm for Phage-CS-NPs (Ph-CS-NPs); and 5-35 nm for Propolis-CS-NPs (Pro-CS-NPs). Nanoparticles displayed peaks between 380-420 nm, 335-380 nm, and below 335 nm for Ag-CS-NPs, Pro-CS-NPs, and Ph-CS NPs, respectively. Throughout the three synthesized nanoparticles, AgCs NPs represented a higher antibacterial effect in combination with phages. It showed MIC against S. sciuri, S. Typhimurium, and P. aeruginosa between 31.2 and 62.2 µg/mL and MBC at 500, 62.5, and 31.2 µg/mL, respectively, while in combination with phages showed MIC at 62.2, 31.2, and 15.6 µg/mL, respectively and MBC at 125, 62.2, and 15.6 µg/mL, respectively. Furthermore, a significant killing efficiency was observed with 16.5-30.1 µg/mL of Ag-CS NPs combined with phages. In conclusion, Ag-CS-NPs with phages present potential bactericidal and inhibitory effects against Gram-positive and Gram-negative bacteria, as well as against the production of biofilms.