Self-targeting nanotherapy based on functionalized graphene oxide for synergistic thermochemotherapy

Nanotherapy based on thermochemotherapy has boomed as a promising alternative for oncotherapy due to the enhanced permeability and retention (EPR) effect. However, a lack of self-targeting capacity prevents nanotherapy from efficiently accumulating in tumor tissue and internalizing into tumor cells, resulting in a suboptimal therapeutic effect. To overcome these bottlenecks, a kind of methotrexate (MTX)-soybean phospholipid (SPC) inclusion complex (MTX-SPC)-modified graphene oxide (CGO) nanotherapy (CGO-MTX-SPC) is constructed by CGO nanosheets as a supporter for MTX-SPC, thereby realizing active-targeting and synergistic thermochemotherapy. As an FDA-approved chemotherapeutic drug, MTX can be regarded as a tumor-targeting enhancer against the folate receptor on account of its similar structure to folic acid (FA). The fabricated CGO-MTX-SPC has a sheet shape with a size of ca. 109 nm and tumor microenvironment-responsive on-demand drug release. It is worth noting that the physiological stability of CGO-MTX-SPC is better than that of CGO while displaying an improved photothermal effect. In addition, CGO-MTX-SPC can specifically recognize tumor cells and then achieve on-demand drug burst release by dual stimuli of internal lysosomal acidity and an external laser. Moreover, in vivo experimental results further demonstrate that CGO-MTX-SPC displays significant enrichment at the tumor location by active targeting mechanisms due to the introduction of MTX-SPC, endowing the synergistic thermochemotherapy effect upon 808 nm laser irradiation and almost thorough tumor elimination while significantly erasing undesirable side effects. Taken together, the design idea of our nanotherapy not only provides a potential tumor-targeting therapeutic strategy but also broadens the drug payload method of two-dimensional nanomaterials.