▎ 摘　　要

A drug delivery system based on carboxymethyl cellulose-grafted graphene oxide loaded by methotrexate (MTX/CMC-GO) with pH-sensitive and controlled drug-release properties was developed in this work. CMC was grafted on graphene oxide by ethylenediamine through hydrothermal treatment. CMC serves as a pH-sensitive trigger, while CMC-GO serves as a drug-carrying vehicle due to the curved layer and large plain surface. Different amounts of drugs could be loaded into CMC-GO nano-carriers by control of the original amount of drug/-carrier ratios. Additionally, low cytotoxicity against NIH-3T3 cells and low in vivo toxicity was observed. In vivo tumor growth inhibition assays showed that MTX/CMC-GO demonstrated superior antitumor activity than free MTX against HT-29 cells. Moreover, prolonged survival time of mice was observed after MTX/CMC-GO administration. The MTX/CMC-GO drug delivery system has a great potential in colon cancer therapy.