Anticancer effect of realgar nanoparticles on mouse melanoma skin cancer in vivo via transdermal drug delivery

Realgar has been used successfully to treat diseases for thousands of years, but its poor water solubility and high toxicity hampered its further medical uses. Here, we first applied transdermal drug delivery system to deliver realgar nanoparticles to investigate its anticancer effect and toxicity in vivo. In this study, MTT assay and flow cytometry analysis demonstrated that realgar significantly suppressed the proliferation and induced apoptosis of B16 melanoma cells in a dose-dependent manner. Transdermal penetration studies in vitro showed realgar nanoparticles could be delivered efficiently through skin. Tests on tumor-bearing C57BL/6 mice displayed that realgar could decrease the tumor volume markedly via transdermal drug delivery compared with the intraperitoneal administration and the control. Hematoxylin–eosin and immunohistochemical staining revealed that it could inhibit angiogenesis. The monitoring of the hepatic injury, body weight, feeding behavior, motor activity, and skin irritation of each animal indicated little toxicity of realgar to mice. The results demonstrated that realgar nanoparticles can be dermally delivered to achieve high efficacy against menaloma in vivo with low toxicity.