Chitosan-capped silver nanoparticles with potent and selective intrinsic activity against the breast cancer cells

Graphical abstract Abstract Herein, we report on the development of chitosan-capped silver nanoparticles (AgNPs-CHI) with an intrinsic activity against breast cancer cells. Following chemical synthesis via a simple, one-pot reaction, the chitosan coating of AgNPs was verified using Fourier-transform infrared and ultraviolet–visible spectroscopies. The physicochemical properties and morphology were characterized using dynamic light scattering, scanning electron microscopy, and transmission electron microscopy. The shelf stability of the optimized platform was tracked for 3 months upon storage at either room temperature or 4°C. Then, the anticancer activities of AgNPs-CHI on human breast cancer cells, MCF-7, versus normal human cells, human skin fibroblasts (HSF), were evaluated via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity assay and tumor-associated biomarkers determination by enzyme-linked immunosorbent assay, in comparison with plain silver nitrate (AgNO3) solution. AgNPs were successfully coated with chitosan and demonstrated acceptable physicochemical properties, with a spherical morphology and high stability upon long-term storage. Although AgNPs-CHI and AgNO3 demonstrated comparable cytotoxicity to MCF-7 cells, AgNPs-CHI resulted in 10-fold lower toxicity to HSF cells, suggesting a higher selectivity. In addition, AgNPs-CHI lowered IL-6 and tumor necrosis factor-alpha levels in MCF-7 cells by 90 and 30%, respectively, compared to 60 and 10% in the case of plain AgNO3. The interesting therapeutic modality presented in this study is promising for potential clinical applications.