Green synthesis of selenium nanoparticles using<em> Acinetobacter</em> sp. SW30: optimization, characterization and its anticancer activity in breast cancer cells

Abstract

The aim of this study was to synthesize selenium nanoparticles (SeNPs) using cell suspension and total cell protein of Acinetobacter sp. SW30 and optimize its synthesis by studying the influence of physiological and physicochemical parameters. Also, we aimed to compare its anticancer activity with that of chemically synthesized SeNPs in breast cancer cells. Cell suspension of Acinetobacter sp. SW30 was exposed to various physiological and physicochemical conditions in the presence of sodium selenite to study their effects on the synthesis and morphology of SeNPs. Breast cancer cells (4T1, MCF-7) and noncancer cells (NIH/3T3, HEK293) were exposed to different concentrations of SeNPs. The 18 h grown culture with 2.7×10 9 cfu/mL could synthesize amorphous nanospheres of size 78 nm at 1.5 mM and crystalline nanorods at above 2.0 mM Na 2 SeO 3 concentration. Polygonal-shaped SeNPs of average size 79 nm were obtained in the supernatant of 4 mg/mL of total cell protein of Acinetobacter sp. SW30. Chemical SeNPs showed more anticancer activity than SeNPs synthesized by Acinetobacter sp. SW30 (BSeNPs), but they were found to be toxic to noncancer cells also. However, BSeNPs were selective against breast cancer cells than chemical ones. Results suggest that BSeNPs are a good choice of selection as anticancer agents.

Specificity of Biogenic Selenium Nanoparticles for Prostate Cancer Therapy With Reduced Risk of Toxicity: An in vitro and in vivo Study

“…Reports on chemically synthesized SeNP suggested lower toxicity and equivalent anticancer activity compared to inorganic and organic selenium compounds (3,11,21,22). Similarly, biogenic SeNPs synthesized by Acinetobacter, Streptomyces, and Halococcus also showed anticancer activity, however, at higher doses (13)(14)(15). Earlier in our study, we have shown that a concentration of 2 µg Se/ml of our sterically stabilized biogenic SeNPs is very effective in inducing TNF/IRF1 mediated necroptosis in PC-3 cells without compromising the viability of human peripheral blood mononuclear cell (hPBMC) (18,19).…”

“…The greater biocompatibility and better stability of these particles are reported to be due to the differential nanostructural arrangements of selenium atoms (12). Some biogenic SeNPs are also reported to induce cell death in various cancer cell lines including Hep-G2, MCF-7, 4T1, and HeLa (13)(14)(15). However, their effect was observed at higher doses.…”

Microbial recovery of metallic nanoparticles from industrial wastes and their environmental applications

“…Moreover, experiments with isolated proteins, presumably involved in metals reduction, have been performed and the results have shown that metals reduction is linked to those specific proteins . In addition, proteins have been reported to be responsible for the reduction and stabilization of NPs acting as capping agents …”

“…11,16,43 In addition, proteins have been reported to be responsible for the reduction and stabilization of NPs acting as capping agents. 15,21,37,40 Enzymes, such as reductases, flavoenzymes, oxidoreductases, hydrogenases, amylases, etc., have been associated with metals reduction. Enzyme activity in culture supernatant evinced participation of extracellular enzymes in metallic NPs biosynthesis.…”

“…Proteins have been found to play an important role in the synthesis of NPs and some of them have been isolated 11,16,43 Also amino and carboxylate groups have been reported to be responsible for the reduction and stabilization of NPs acting as capping agents. 15,21,37,40 Other reported mechanisms specify the interactions governing the process, some of them have referred to complexes formation, film diffusion or electrostatic interactions as the first step, followed by pore diffusion or ligand substitution until bioreduction is achieved, and nucleation occurred as a final step. 37,42,58 However, it cannot be assumed that these mechanisms are general or applicable for all conditions, since they can vary according to experimental conditions, physicochemical parameters, strain used, metabolic pathways, etc.…”