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.