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In this study, different positively charged niosomal formulations containing sorbitan esters, cholesterol and cetyl trimethyl ammonium bromide were prepared by film hydration method for the entrapment of autoclaved Leishmania major (ALM). Size distribution pattern and stability of niosomes were investigated by laser light scattering method and ALM encapsulation per cent was measured by the bicinchoninic acid method. Finally, the selected formulation was used for the induction of the immune response against cutaneous leishmaniasis in BALB/c mice. Size distribution curves of all the formulations followed a log-normal pattern and the mean volume diameter was in the range 7.57-15.80 µm. The mean volume diameters were significantly increased by adding Tween to Span formulations (p < 0.05). The percentage of ALM entrapped in all formulations varied between 14.88% and 36.65%. In contrast to ALM, in vivo studies showed that the niosomes containing ALM have a moderate effect in the prevention of cutaneous leishmaniasis in BALB/c mice.

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Background: Recent theranostic (therapeutic or diagnostic) applications of tellurium nanoparticles have attracted a great interest for development of diff erent methods for synthesis of this valuable nanostructure, especially via biological resources. Objectives: In the present study, the antimicrobial and antioxidant eff ects of the tellurium nanorods (Te NRs) biosynthesized by a bacterial strain Pseudomonas pseudoalcaligenes strain Te were evaluated. Materials and Methods:The antimicrobial eff ect of Te NRs and potassium tellurite against diff erent bacterial and fungal pathogens was assessed by microdilution method. Furthermore, the disk diff usion method was used to evaluate the antibacterial eff ect of the biogenic Te NRs and potassium tellurite against methicillin-resistant Staphylococcus aureus, alone or in combination with various antibiotics. Also, the biogenic Te NRs were investigated for antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power assay. Results: Transmission electron micrograph (TEM) of the purifi ed Te NRs showed individual and rod-shaped nanostructure (~22 nm diameter by 185 nm in length). Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antibacterial and antifungal activity compared to the Te NRs. The measured IC 50 for the biogenic Te NRs (i.e. DPPH radical scavenging activity) was found to be 24.9 μg.mL -1 , while, K 2 TeO 3 has represented only 17.6 ± 0.8 % DPPH radical scavenging eff ect at the concentration of 160 μg.mL -1 . The reducing power assay revealed a higher electron-donating activity for Te NRs compared to K 2 TeO 3 . Conclusions: Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antimicrobial and antifungal activity than Te NRs. Te NRs didn't show the antibacterial eff ect against the tested bacterial strain: MRSA and showed an inhibitory eff ect and antibacterial activity of the eff ective antibiotics. However, more studies should be performed to explore the action mechanism of the produced biogenic Te NRs.