The structural changes in DNA caused by the combined effects of silver nanoparticles (Ag NPs) and doxorubicin (DOX) was investigated along with their corresponding inhibitory roles in the growth of T47D and MCF7 cells. The UV-visible titration studies showed that DOX + AgNPs could form a novel complex with DNA and this interaction is in the interface between the value induced by electrostatic and intercalative binding. The values of binding constants revealed that DOX + AgNPs interact more strongly with DNA as compared to Ag NPs or DOX alone. Our CD data revealed that although Ag NPs and DOX alone could alter DNA structure, this combination leads to transition of DNA conformation to an ordered and compact molecular form so called &phis-type, considering that DNA is relatively thermally stable in the condition used. Thus, we observed that DOX + AgNPs induces conformational change on DNA. The anticancer property of DOX + AgNPs by MTT assay, DAPI stain and flow cytometry analyses demonstrated that this combination can tremendously diminish proliferation of T47D and MCF7 cells compared to DOX or Ag NPs alone. Furthermore, this combination was comparatively non-toxic towards the human endometrial stem cells proliferation. Collectively, these results reveal that DOX + AgNPs could proffer a novel strategy for the development of promising and efficient chemotherapy agents.

For many years, the chemotherapeutic agent doxorubicin (DOX) has been used to treat various cancers; however, DOX initiates several critical adverse effects. Many studies have reported that non-thermal atmospheric pressure plasma can provide novel, but challenging, treatment strategies for cancer patients. To date, tissues and cells have been treated with plasma-activated medium (PAM) as a practical therapy. Consequently, due to the harmful adverse effects of DOX, we were motivated to elucidate the impact of PAM in the presence of DOX on MCF-7 cell proliferation. MTT assay, N-acetyl-L-cysteine (NAC) assay, and flow cytometry analysis were utilized in this research. The results demonstrated that 0.45 µM DOX combined with 3-min PAM significantly induced apoptosis (p< 0.01) through intracellular ROS generation in MCF-7 when compared with 0.45 µM DOX alone or 3-min PAM alone. In contrast, after treatment with 0.45 µM DOX plus 4-min PAM, cell necrosis was increased. Hence, DOX combined with 4-min PAM has cytotoxic effects with different mechanisms than 4-min PAM alone, in which the number of apoptotic cells increases. Although further investigations are crucial, low doses of DOX plus 3-min PAM could be a promising strategy for cancer therapy. The findings from this research may offer advantageous and innovative clinical strategies for cancer therapy using PAM.