Synthesis of silver and copper nanoparticle using Spirulina platensis and evaluation of their anticancer activity.

The present research displays the green synthesis of stable silver nanoparticles (Ag-NPs) and copper oxide nanoparticles (CuO-NPs). The aqueous solution of Spirulina platensis (blue green algae) source was used as a reducing and capping agent and this study assessed the cytotoxicity of Ag- and CuO-NPs on three cancer cell cultures: A549 (lung cancer), HCT (human colon cancer), Hep2 (laryngeal carcinoma cancer) and normal cell (WISH). For NPs characterization, the UV/Vis spectroscopy was used where their formation and crystallinity were proven with λmax values for Ag- and CuO-NPs of 425 and 234 nm, respectively. According to X-ray diffraction and transmission electron microscopy (TEM), Ag-NPs were spherical in shape (size 2.23-14.68 nm) and CuO-NPs were small (size 3.75-12.4 nm). Zeta potential analysis showed the particles potential, which was recorded by -14.95 ± 4.31 mV for Ag-NPs and -21.63 ± 4.90 mV for CuO-NPs. After that, Ag- and CuO-NPs were assessed for anticancer properties against A549, HCT, Hep2 and WISH. IC50 of Ag-NPs recorded 15.67, 12.94, 3.8 and 10.44 µg/ml for WISH, A549, HCT and Hep2, respectively. IC50 for CuO-NPs was recorded as 32.64, 54.59, 3.98 and 20.56 µg/ml for WISH, A549, HCT and Hep2 cells, respectively. Safety limits for WISH and A549 were achieved 98.64% by 2.44 µg/ml and 83.43% by 4.88 µg/ml of Ag-NPs, and it was found to be 97.94% by 2.44 µg/ml against HCT, while that for Hep2 is 95.9% by 2.44 µg/ml. Concerning the anticancer effect of CuO-NPs, the safety limit was recorded as 88.70% by 2.44 and 98.48% by 4.88 µg/ml against WISH and A549, while HCT reached 89.92% by 2.44 µg/ml and Hep2 was 83.33% by 4.88 µg/ml. Green nanotechnology applications such as Ag-NPs and CuO-NPs have numerous benefits of ecofriendliness and compatibility for biomedical applications such as anticancer effects against cancer cells.

The Integrated Amendment of Sodic-Saline Soils Using Biochar and Plant Growth-Promoting Rhizobacteria Enhances Maize (Zea mays L.) Resilience to Water Salinity.

The utilization of low-quality water or slightly saline water in sodic-saline soil is a major global conundrum that severely impacts agricultural productivity and sustainability, particularly in arid and semiarid regions with limited freshwater resources. Herein, we proposed an integrated amendment strategy for sodic-saline soil using biochar and/or plant growth-promoting rhizobacteria (PGPR; Azotobacter chroococcum SARS 10 and Pseudomonas koreensis MG209738) to alleviate the adverse impacts of saline water on the growth, physiology, and productivity of maize (Zea mays L.), as well as the soil properties and nutrient uptake during two successive seasons (2018 and 2019). Our field experiments revealed that the combined application of PGPR and biochar (PGPR + biochar) significantly improved the soil ecosystem and physicochemical properties and K+, Ca2+, and Mg2+ contents but reduced the soil exchangeable sodium percentage and Na+ content. Likewise, it significantly increased the activity of soil urease (158.14 ± 2.37 and 165.51 ± 3.05 mg NH4+ g-1 dry soil d-1) and dehydrogenase (117.89 ± 1.86 and 121.44 ± 1.00 mg TPF g-1 dry soil d-1) in 2018 and 2019, respectively, upon irrigation with saline water compared with non-treated control. PGPR + biochar supplementation mitigated the hazardous impacts of saline water on maize plants grown in sodic-saline soil better than biochar or PGPR individually (PGPR + biochar > biochar > PGPR). The highest values of leaf area index, total chlorophyll, carotenoids, total soluble sugar (TSS), relative water content, K+ and K+/Na+ of maize plants corresponded to PGPR + biochar treatment. These findings could be guidelines for cultivating not only maize but other cereal crops particularly in salt-affected soil and sodic-saline soil.