<p>Synthesis of Silver Nanoparticles Using a Novel Cyanobacteria <em>Desertifilum</em> sp. extract: Their Antibacterial and Cytotoxicity Effects</p>

Abstract

Background: The emergence of multi drug-resistant (MDR) bacterial infections and cancer has necessitated the development and discovery of alternative eco-safe antibacterial and anticancer agents. Biogenic fabrication of metallic nanoparticles is an emerging discipline for production of nanoproducts that exert potent anticancer and antibacterial activity, and do not suffer from the limitations inherent in physiochemical synthesis methods. Methodology: In this study, we isolated, purified, and characterized a novel cyanobacteria extract (Desertifilum IPPAS B-1220) to utilize in biofabrication of silver nanoparticles (D-SNPs). D-SNPs were produced by adding Desertifilum extract to silver nitrate solution under controlled conditions. Biofabrication of D-SNPs was confirmed using a UV-Vis spectrophotometer. The resultant D-SNPs were characterized using XRD, FTIR, SEM, and TEM. The toxicity of D-SNPs against five pathogenic bacteria and three cancer cell lines (MCF-7, HepG2, and Caco-2) was evaluated. Results: Formation of D-SNPs was indicated by a color change from pale yellow to dark brown. The peak of the surface plasmon resonance of the D-SNPs was at 421 nm. The XRD detected the crystallinity of D-SNPs. FTIR showed that polysaccharides and proteins may have contributed to the biofabrication of D-SNPs. Under SEM and TEM, the D-SNPs were spherical with diameter ranges from 4.5 to 26 nm. The D-SNPs significantly suppressed the growth of five pathogenic bacteria, and exerted cytotoxic effects against MCF-7, HepG2, and Caco-2 cancer cells with IC 50 values of 58, 32, and 90 µg/mL, respectively. Conclusion: These findings showed for the first time the potentiality of novel cyanobacteria strain Desertifilum IPPAS B-1220 to fabricate small SNPs that acted as potent anticancer and antibacterial material against different cancer cell lines and pathogenic bacterial strains. These findings encourage the researchers to focus on cyanobacteria in general and especially Desertifilum sp. IPPAS B-1220 for synthesizing different NPs that opening the window for new applications.

<p>Cyanobacteria – A Promising Platform in Green Nanotechnology: A Review on Nanoparticles Fabrication and Their Prospective Applications</p>

“…32 The natural sources used in biofabrication of NPs vary from unicellular to multicellular organisms, moreover; this process can be carried out in the presence of single proteins, enzymes, pigments, etc. 21 The unicellular organisms include bacteria, 44 cyanobacteria, 31 and diatoms, 45 while multicellular organisms include algae and plant. 46,47 The variety of potential natural sources and biomolecules facilitate the production of NPs with different unique properties.…”

“…NPs are also subjected to various characterization analyses to assess their physical and chemical properties, including size, distribution, dispersion, stability, charge, and surface morphology. 48,49 These analyses use spectroscopic techniques such as ultraviolet (UV)-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), zeta potential, dynamic light scattering, and nuclear magnetic resonance spectroscopy to determine wavelength ranges, 27 and the chemical composition of biocoats surrounding biogenic NPs, 31 and to confirm the formation of NPs, as well as characterizing their charge and hydrodynamic diameter. 50 X-ray based analyses such as X-ray diffraction (XRD), 49 X-ray photo-electron spectroscopy (XPS), 23 and energy dispersive spectroscopy (EDAX or EDS) are employed to evaluate composition, structure and crystal phase, structure and crystal phase.…”

“…Several reports describe the cell biomass filtrate synthesis approach, in which microorganism cultures are centrifuged and the pellets washed at least three times with distilled water to eliminate any excess metal from the medium. 31,32,75 Then, the cleaned pellets are freeze-dried using a lyophilizer or dried in an oven almost at 40 °C, then crushed using a mortar and pestle. The resulting fine powder is mixed with distilled water then filtrated using Whatman filter paper.…”

“…In this method, active biomoieties such as proteins and enzymes in the cells filtrate have significant roles in the biofabrication and stabilization of NPs. 31 Other route mentioned by Hassan et al in which cell biomass collected at mid-exponential phase and wash several times to exclude any trace elements then soaked in distilled water for specific time. Afterward, the mixture is centrifuged, and the supernatant is used for NPs synthesis.…”

“…Thus, they represent important nanotechnology-mediated microorganisms that can act as nanobiofactories for NPs. 31,32 Although there have been several detailed reviews of biological synthesis using microorganisms, few studies have focused on synthesis of NPs using cyanobacteria.…”