بیوسنتز و تعیین خصوصیات فیزیکوشیمیایی و سمیت سلولی نانوذرات سلنیوم تولید شده توسط استرپتومایسس لاواندوله FSHJ9 علیه رده سلولی MCF-7

Background and Objectives: Due to the unique physicochemical properties of selenium nanoparticles (Se NPs), identification of microbial strains capable to biosynthesize Se NPs has recently attracted attention. The current study aimed at introducing Se NPs producing actinomycete strain, characterizing Se NPs as well as evaluating its cytotoxic effect against breast cancer cell line (MCF-7). Materials and Methods: In the present laboratory investigation, first, the Se NPs producing strain was isolated from soil samples. The selected isolate was then identified using morphological and biochemical examinations as well as 16S rDNA sequencing protocol. The UV-visible spectrum, particle-size distribution (PSD) pattern, Fourier-transform infrared (FTIR), and energy-dispersive X-ray (EDX) profiles of the nanostructures as well as transmission electron microscope (TEM) image of Se NPs were determined. In order to evaluate the cytotoxicity of the Se NPs, the MTT (Methylthiazolyldiphenyl-tetrazolium bromide) based colorimetric protocol was applied where the viability percent was firstly determined and then the related IC50 (Half inhibitory concentration) was calculated. Results: The selected bacterial isolate was identified as Streptomyces lavendulae FSHJ9. TEM micrographs of the biogenic Se NPs exhibited spherical nanostructures with the size range of 28–123 nm. The FTIR pattern showed no functional group present on the surface of Se NPs. The obtained results of cytotoxicity revealed that IC50 of Se NPs (77.1±42.23 µg/mL) was more than IC50 of sodium selenite (3.0±41.53 µg/mL). Conclusion: The results of the present study showed that Streptomyces lavendulae FSHJ9 was able to produce Se NPs. The produced biogenic Se NPs, after performing complementary studies, might be applied as supplement in human food and animal feeding. Key words: Selenium nanoparticles, Biosynthesis, Streptomyces, Cytotoxicity, MCF-7 cell line   Funding: This study was funded by Kerman University of Medical Sciences. Conflict of interest: None declared. Ethical approval: The Ethics Committee of Kerman University of Medical Sciences approved the study (930160).   How to cite this article: Shakibaie M, Jafari M, Ameri A, Rahimi H.R, Forootanfar H. Biosynthesis and Physicochemical Characterization, and Cytotoxic Evaluation of Selenium Nanoparticles Produced by Streptomyces Lavendulae FSHJ9 Against MCF-7 Cell Line. J Rafsanjan Univ Med Sci 2018; 17 (7): 625-38. [Farsi]