Biosynthesis, characterization and biomedical potential of Arthrospira indica SOSA-4 mediated SeNPs.

The use of aqueous cyanobacterial extracts for selenium nanoparticle (SeNP) synthesis is considered green, cost-effective, and eco-friendly technology that is more advanced than physical and chemical methods. In the current study, an aqueous extract of Arthrospira indica SOSA-4 was used as a reducing and stabilizing agent for the green synthesis of SeNPs. The UV-Visible absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-Ray diffraction, Raman spectroscopy, Atomic force microscopy (AFM), Scanning electron microscopy-Energy Dispersive X-Ray spectroscopy(SEM-EDX), and Transmission electron microscopy (TEM) were performed to characterize the biosynthesized SeNPs. Gas chromatography-Mass spectrometry (GC-MS) was also performed to know the composition of the cyanobacterial extract. SEM, TEM, and AFM showed the average size of SeNPs to be 8.5 nm, 9 nm, and 8.7 nm respectively. FT-IR analysis demonstrated the presence of functional groups on the SeNPs that acted as stabilizing agents. XRD pattern and Raman spectroscopy showed the amorphous nature of SeNPs. Synthesized SeNPs showed significant antioxidant activity in DPPH, FRAP, SOR, and ABTS assay. SeNPs showed good anti-microbial activity against Staphylococcus aureus, Escherichia coli, Candida albicans, Candida glabrata, and Candida tropicalis and good anti-cancer activity in MTT assay, Trypan assay, and Flow cytometry analysis against MCF-7, SiHa, and SW480 cell lines. Non-toxicity of SeNPs against normal cell line (HEK-293) was an additional property that affirmed its potential as a bio-compatible nanomaterial.

Designing and validation of genus-specific primers for human gut flora study

The aim of this study, was to design and validate 16S rRNA targeted oligonucleotide genus specific primers for amplifying the predominant members of gut flora using polymerase chain reaction. Primers were validated against human faecal samples. Gut flora of a normal individual was compared with that of two diseased individuals. Our observations showed that the genera Lactobacillus, Bacteroides, Peptococcus, Bifidobacterium, and E. coli were invariably present in all studied subjects however, the absence of butyrate producing bacteria Ruminococcus and Peptostreptococcus were significant. Presence of the members of the genus, Campylobacter in both the diseased samples were also unusual.