▎ 摘　　要

Functionalized graphene oxide (CGO-cRGDyK/POLO) nanosheets were designed and developed for targeted drug delivery to integrin expression. The anticancer drug cambretastain A4 (CA4) was conjugated onto the CGO-cRGDyK/POLO nanosheets. The tumor targeting ligands, cyclic arginine-glycine-aspartic acid-tyrosine-lysine pentapeptides (cRGDyK), were conjugated to carboxylated graphene oxide (CGO) nanosheets, and poloxamer 188 (POLO) was rendered to make the CGO-cRGDyK nanosheets stable. The CGO-cRGDyK/POLO nanosheets exhibited good cytocompatibility, high CA4-loading capacity (0.6872 +/- 0.0121 mg mg(-1)) via pi-pi stacking or hydrophobic interactions, and controlled release in vitro. The MTT assays showed that the CGO-cRGDyK nanosheets had greater antitumor effects on Hela cells than CGO/POLO nanosheets but lower cytotoxicity on the L02 cells than free CA4. In addition, the cellular uptake of CGO-cRGDyK/POLO nanosheets was increased significantly in human umbilical vein endothelial cells (the integrins-overexpressed cells) compared to the normal L02 cells. Thus, the CGO-cRGDyK/POLO nanosheets are an appealing platform for cancer chemotherapy.