Doxorubicin-conjugated pH-responsive gold nanorods for combined photothermal therapy and chemotherapy of cancer

Cancer chemotherapy can be hindered by drug resistance which leads to lower drug efficiency. Here, we have developed a drug delivery system that tethers doxorubicin to the surface of gold nanorods via a pH-sensitive linkage (AuNRs@DOX), for a combined photothermal and chemical therapy for cancer. First, AuNRs@DOX is ingested by HepG2 liver cancer cells. After endocytosis, the acidic pH triggers the release of doxorubicin, which leads to chemotherapeutic effects. The gold nanorods are not only carriers of DOX, but also photothermal conversion agents. In the presence of an 808 nm near-infrared laser, AuNRs@DOX significantly enhance the cytotoxicity of doxorubicin via the photothermal effect, which induces elevated apoptosis of hepG2 cancer cells, leading to better therapeutic effects in vitro and in vivo.