Potent activity of bioconjugated peptide and selenium nanoparticles against colorectal adenocarcinoma cells.

Nanomaterial based anticancer treatment is promising nowadays because of their small size that can penetrate and interact both inside and outside the cell surface. In this study, a simple protocol was followed for the conjugation of the biologically synthesized selenium nanoparticles (SeNPs) and short chain synthetic peptide. SeNPs was synthesized by using the culture supernatant of Streptomyces griseoruber, actinomycetes isolated from the soil. The short chain peptide Boc-L-F-OMe was synthesized by the conventional solution phase chemistry using a racemization-free fragment condensation strategy. Peptide interaction with different anticancer receptors was preliminarily studied by docking studies. Biosynthesized SeNPs was conjugated with short chain synthetic peptides by means of cysteine conjugation. Characterization of SeNPs with peptide was done by UV-visible spectroscopy and DLS that showed the red shift in the peak and increase in average particle size and zeta potential, respectively. Bioconjugated SeNPs- peptide was tested for its cytotoxicity against the colon cancer cell line HT-29. Bioconjugated SeNPs-peptide showed enhanced cytotoxic activity when compared to the peptide and nanoparticle alone that was tested at 10-50 µg/ml concentration. Further apoptotic studies were done by AO/PI staining and DNA fragmentation assay that confirms the cytotoxicity of the conjugates. Novel peptide-SeNPs conjugates tested in our study has a significant anticancer activity that can be potentially used for targeting the cancer cells.

Extracellular Synthesis of Selenium Nanoparticles from an Actinomycetes Streptomyces griseoruber and Evaluation of its Cytotoxicity on HT-29 Cell Line.

BACKGROUND: Selenium nanoparticles (SeNPs) have gained significant importance because of its bioavailability, least toxicity, its interaction with proteins and its biocompatibility. OBJECTIVE: In the present study, the extracellular synthesis of SeNPs was carried out by using culture supernatant of Streptomyces griseoruber, an Actinomycetes member isolated from the soil and cytotoxicity was tested on HT-29 cell line. METHODS: Culture supernatant was mixed with 1mM sodium selenite for the biosynthesis of SeNPs. Characterisation of the synthesised SeNPs was done by UV-Visible spectrophotometer, FTIR, XRD, DLS and HR-TEM. The cytotoxicity of nanoparticles on HT-29 cell line was studied by MTT assay and with different staining procedure. RESULTS: Bioreduction of SeNPs was confirmed by UV-Visible spectrophotometer that showed the peak at 575 nm. Size and distribution of the biosynthesised SeNPs were analysed by HR-TEM that showed the formation of particle size in the range of 100-250nm. The synthesised SeNPs showed good cytotoxic activity against HT-29 cell line with 40.5%, 33% and 23.7% of cell viability at 2µg/ ml, 4µg/ml and 30µg/ml concentration respectively. CONCLUSION: The present study reports the simple and eco-friendly synthesis of SeNPs that showed good cytotoxic activity against HT-29 cell line suggesting that biogenic SeNPs could be a potential chemotherapeutic agent.

Actinomycetes mediated synthesis of gold nanoparticles from the culture supernatant of Streptomyces griseoruber with special reference to catalytic activity.

Biogenic synthesis of nanoparticles has received a tremendous attention from the past few decades. The significant progress in the field of nanotechnology has resulted in a cost-effective and eco-friendly process for nanoparticle synthesis. In the present study, the extracellular synthesis of gold nanoparticles was carried out using culture supernatant of Streptomyces griseoruber, actinomycetes isolated from the soil. Bioreduction of gold nanoparticles was confirmed by UV-visible spectrophotometer that showed the peak between 520 and 550 nm. The crystalline nature and mean size of the GNPs were confirmed using XRD. FTIR revealed the possible functional group that could be useful in immobilisation and stabilisation of GNPs. Size and distribution of the biosynthesized GNPs were analysed by HR-TEM that showed the formation of GNPs in the range of 5-50 nm. The synthesised GNPs showed good catalytic activity for the degradation of methylene blue. The study shows the rapid and eco-friendly synthesis of GNPs from Streptomyces griseoruber, and this is the first report on the catalytic activity of GNPs from actinomycetes so far.