Spider Toxin Peptide Lycosin-I Functionalized Gold Nanoparticles for in vivo Tumor Targeting and Therapy.

Cell penetrating peptides (CPPs) are commonly utilized for intracellular delivery of functional materials to circumvent biomembrane barrier. However, further application of CPPs is hindered by lacking selectivity toward targeted cells. The spider venom peptide, lycosin-I, is a CPP with potent cytotoxicity to cancer cells, which might enable lycosin-I to deliver functional materials into cancer cells selectively. In this study, we demonstrated that the lycosin-I-conjugated spherical gold nanoparticles (LGNPs) not only exhibited efficient cellular internalization efficiency toward cancer cells but also displayed unprecedented selectivity over noncancerous cells. Although LGNPs were removed from the living circulatory system via reticuloendothelial system-dominant clearance modes without noticeable adverse effects to animals, they actually displayed active tumor-targeting effects and efficient accumulation in tumors in vivo. Furthermore, the potential application of this platform for cancer therapy was explored by lycosin-I-conjugated gold nanorods (LGNRs). LGNRs exhibited selective intracellular translocation towards cancer cells and efficient photothermal effect under near infrared (NIR, 808 nm) irradiation, which consequently killed cancer cells in vitro and in vivo effectively. Therefore, the established LGNPs and LGNRs possessed great potential in cancer-targeting delivery and photothermal therapy.