Photo-induced biosynthesis of silver nanoparticles from aqueous extract of Dunaliella salina and their anticancer potential

•Green synthesis of AgNPs using extremophilic green alga Dunaliella salina•AgNPs showed toxicity towards cancer cell line while no impact on normal cells.•Impact of AgNPs and Cisplatin were almost similar on two cell lines in many aspects.•First report of green synthesis of silver nanoparticles from Dunaliella salina

The synthesis of silver nanoparticles (AgNPs) via green route, using biological entities is an area of interest, because one of the potential applications in the nanomedicine. In the present study, we have developed photo-induced, ecofriendly, low cost method for biosynthesis of the stable silver nanoparticles using aqueous extract of Dunaliella salina (AED) which act as both reducing as well as stabilizing agent. Biosynthesis of the AgNPs was optimized as: sunlight exposure (30 min), AED (5% (v/v)) and AgNO3 (4 mM). Biosynthesis of AgNPs was monitored by using UV-Vis spectroscopy which exhibited sharp SPR band at 430 nm after 30 min of bright sunlight exposure. SEM and TEM analyses confirmed the presence of spherical AgNPs with average size of 15.26 nm. Crystalline nature of AgNPs was confirmed by SAED and XRD analyses where Braggs reflection pattern at (111), (200), (220) and (311) corresponded to face centered cubic crystal lattice of metallic silver. FTIR analysis revealed the involvement of various functional groups present in AED. AFM analysis confirmed the average surface roughness of synthesized AgNPs as 8.48 nm. AgNPs were also screened for anticancer potential using assay of calcein AM/PI, Annexin/PI and cancer biomarkers against cancer cell line (MCF-7), while normal cell line (MCF-10A) were kept as control. Interestingly, anticancer potential was comparable to the known anticancer drug (Cisplatin), and was not detrimental to the normal cell line. Therefore, such green synthesized AgNPs may be explored as anticancer agent.

Graphical AbstractPhoto induced green synthesis of silver nanoparticles (stable with average size of 15.26 nm), from the aqueous extract of a green alga Dunaliella salina (AED), showed anticancer potential. A comparison of cancer (MCF7) and normal (MCF10A) cell lines after exposure to AgNPs and anticancer drug (Cisplatin), clearly demonstrated that such AgNPs may be used as anticancer agent.Download high-res image (191KB)Download full-size image