Graphitic carbon nanocages as new photothermal agent and drug Carrier for 980-nm-laser-driven cancer therapy

Graphitic carbon nanocage (GCNC) is an important member of the graphene-based nanomaterial family. Here, GCNCs were synthesized and used for cancer photothermal therapy (PTT) induced by 980-nm laser irradiation at a low power density (0.28W/cm(2)). Upconversion nanoparticles (UCNPs) were also synthesized and used in solution to confirm laser irradiation of samples containing GCNCs, cancer cells, or mouse tumors. The photothermal conversion efficiency of the as-synthesized GCNCs on 980-nm laser irradiation was similar to that of multiwalled carbon nanotubes (MWCNTs) and reduced graphene oxide. Although both GCNCs and MWCNTs did not cause genomic DNA damage in cells, the cell cycle dysregulation caused by MWCNTs was more serious than that caused by GCNCs. Furthermore, the synthesis of GCNCs is much simpler and cheaper than that of MWCNTs. Five types of small-molecule drug were respectively incorporated into the GCNCs. The GCNCs irradiated with a 980-nm laser effectively killed cancer cells and inhibited tumor growth, and the cell-killing efficiency of the laser-triggered drug-loaded GCNCs was significantly higher than those achieved using PTT with GCNCs and cytotoxic drugs. The results of this work will enable biomedical applications of GCNCs to be greatly improved. (C) 2018 Published by Elsevier Ltd.