▎ 摘　　要

Breast cancer is the second most common cancers among female worldwide. The current treatment strategies includes surgery, chemo-, radio- and hormone-therapy. Nevertheless, breast cancer still accounts for more than 20% of all female cancer deaths, presumably, due to the lack of specificity to target site or the development of drug resistance. Graphene nanoribbons (GNRs) are one of the promising platforms that show efficient cellular internalization and high target specificity for cancer cells. Herein, oxidized graphene nanoribbons (OGNRs), decorated with folic acid (FA) and loaded with the selective estrogen receptor modulator, tamoxifen citrate (TC), were prepared from multi-walled carbon nanotubes using the longitudinal unzipping method. The synthesized TC-loaded OGNRs-FA showed multi-layered structure with drug loading efficiency of 56%. In vitro release studies showed a pH-dependent release of TC from OGNRs. In addition, TC loaded onto OGNRs significantly reduces cell viability and induces apoptosis in MCF-7 and MDA-MB-231 breast cancer cell lines in concentration and-time dependent manner. Most importantly, cellular uptake studies revealed that surface decoration of OGNRs with FA significantly contributed to the preferential cellular internalization of TC-loaded OGRNs-FA by breast cancer cells, compared to naked OGNRs. In vivo pharmacokinetic study suggests that drug loading onto OGNRs-FA remarkably reduced the premature drug release in systemic circulation and, consequently, could enhance the availability of drug payload at the target site. Collectively, OGNRs-FA might represent a promising platform for efficient and selective delivery of tamoxifen to breast cancer cells. However, deep understanding of the in vivo fate and long-term toxicity of OGNRs-FA is crucial for further clinical application.