Green synthesis of anisotropic silver nanoparticles with potent anticancer activity using Taxus baccata extract

Abstract

Anisotropic silver nanoparticles with controlled shape and size were synthesized by a simple, efficient and eco-friendly method using Taxus baccata extracts as reducing, capping and stabilizing agents. The monodispersed nanoparticles showed narrow size distribution with an average of 75.1 nm and high stability in aqueous colloidal solutions. Different factors including the concentration and the type of plant extract, the concentration of silver nitrate, pH and temperature were investigated in order to synthesize silver nanoparticles of desired size and shape. Surprisingly, the type of plant extract was the main parameter and remarkably affected the physical, chemical and cytotoxic properties of the nanoparticles. On the basis of AFM and TEM results, the use of an aqueous extract led to the synthesis of spherical nanoparticles while stable colloidal silver nanoparticles of hexagonal and truncated triangular shapes with characteristic absorption maxima of 530 and 690 nm, respectively, were synthesized in the presence of high concentrations of ethanolic extract. The strong adsorption of Taxus metabolites on the surfaces of nanoparticles was confirmed by FTIR and TGA analyses. The MTT assay revealed potent anticancer effects of the aqueous extract synthesized nanoparticles on MCF-7 cells with an IC₅₀ value of 0.25 μg mL⁻¹ after 48 hours incubation time. According to the results, the present reported biogenic method has great potential for simple and efficient development of novel multifunctional nanoparticles for tracking, imaging, and therapy of cancer cells.