More than 22% of the world's agricultural land is saline, and this trend continues to increase with climate changes. Salinity stress causes leaf color change, osmotic stress, ionic toxicity, prevents growth, photosynthesis and plant performance. Due to their size less than micron, metal nanoparticles have a great absorption and transmission power in plants. Salinity stress is a major problem in hot and dry areas under tomato cultivation. For this purpose, investigating the mutual effects of the size and type of zinc oxide and iron oxide nanoparticles on the improvement and change of growth and increasing the resistance to salt stress in tomato plants of the early urbana variety were carried out in the form of a completely randomized and factorial design with 4 replications, at a significant level of 5%. In this research, zinc oxide nanoparticles in 25 and 50 nm sizes, iron oxide in 25 nm sizes and sodium chloride in 0 and 75 mM levels were used. Nanoparticles and salinity treatments were both applied to the plants. The results showed that salt stress led to a decrease in plant growth parameters such as shoot and root length, leaf area, RWC, ion leakage. Also, NaCl led to an increase in the accumulation of prolin and other aldehydes, sodium, iron and zinc. The application of nanoparticles had a slight effect in stress-free conditions, but in stressed conditions, these two nanoparticles alone and especially in combination neutralized the effect of salinity and reduced the damage caused by salinity stress.

Background: The threat of antimicrobial resistance is increasing worldwide. Niosomes are a new drug delivery system that increases the antimicrobial potential of antibiotics. Accordingly, this study aimed to evaluate the antibacterial activity of niosomes loaded with curcumin-silver nanoparticles (Cur-AgNPs) and curcumin-copper nanoparticles (Cur-CuNPs). Methods: Initially, a unique combination of metal and curcumin nanoparticles was prepared in free and encapsulated forms to investigate the synergistic effects of the two drugs and to evaluate them through a niosomal carrier. Particle size and polydispersity index were measured using dynamic light scattering (DLS), and entrapment efficiency (EE) was measured through indirect centrifugation. The rate of drug release from the loaded niosomes was assessed through in vitro dialysis. Finally, the antibacterial activity of Cur-AgNPs and Cur-CuNPs loaded niosomes on Staphylococcus aureus and Pseudomonas aeruginosa were measured. Results: The curcumin-loaded niosomal formulations and the simultaneous combination of Cur-AgNPs and Cur-CuNPs had an optimum particle size of less than 200 nm and uniform dispersion. These formulations also showed high entrapment efficiencies and slow release for more than 72 hours. Conclusion: A significant increase in antibacterial activity was observed when using curcumin in combination with metal nanoparticles loaded in niosomes, indicating that the concomitant use of metal nanoparticles and curcumin had a synergistic effect in inhibiting bacterial growth.