Interaction studies between biosynthesized silver nanoparticle with calf thymus DNA and cytotoxicity of silver nanoparticles

•Interaction between CTDNA and biosynthesized SNP.•Groove binding with partial intercalation of SNP to CTDNA.•Cytotoxicity and cell staining of SNP on HeLa cell line.

The interaction of calf thymus DNA (CTDNA) with silver nanoparticles (SNP) has been investigated following spectroscopic studies, analysis of melting temperature (Tm) curves and hydrodynamic measurement. In spectrophotometric titration and thermal denaturation studies of CTDNA it was found that SNP can form a complex with double-helical DNA and the increasing value of Tm also supported the same. The association constant of SNP with DNA from UV–Vis study was found to be 4.1 × 103 L/mol. The fluorescence emission spectra of intercalated ethidium bromide (EB) with increasing concentration of SNP represented a significant reduction of EB intensity and quenching of EB fluorescence. The results of circular dichroism (CD) suggested that SNP can change the conformation of DNA. From spectroscopic, hydrodynamic, and DNA melting studies, SNP has been found to be a DNA groove binder possessing partial intercalating property. Cell cytotoxicity of SNP was compared with that of normal silver salt solution on HeLa cells. Our results show that SNP has less cytotoxicity compared to its normal salt solution and good cell staining property.

Graphical abstractInteraction between biosynthesized silver nanoparticles and calf thymus DNA and study of silver nanoparticles toxicity as well as cell staining ability has been carried out in this work.Figure optionsDownload full-size imageDownload as PowerPoint slide