Recent advances in photothermal and RNA interfering synergistic therapy

As a new treatment technique, photothermal therapy (PTT) has aroused worldwide attention in cancer treatment, mainly due to its excellent absorption ability, easy regulation, and biodegradability. Photothermal conversion materials with enhanced permeability and retention effect can be targeted easily to tumor tissue. They can accumulate efficiently to tumor tissues and allow normal tissues and organs not to be affected by temperature, thus significantly helping to reduce the systemic toxicity and improve the antitumor effect. However, PTT alone often suffers from therapeutic resistance and reduced therapeutic efficacy, due to photothermal nanomaterial-mediated fundamental cellular defense mechanism of heat shock response, which could be inhibited by small interfering RNA (siRNA). Nevertheless, photothermal conversion materials as an excellent siRNA delivery carrier may considerably enhance the delivery efficiency of siRNA. Therefore, photothermal and RNA interfering (RNAi) synergistic therapy has recently aroused extensive attention in tumor treatment. In this review, we mainly summarize the recent advances of photothermal and RNAi synergistic therapy, including some synergistic therapeutic nanoplatforms of inorganic and organic photothermal materials and other combined therapies such as combining with small molecular antitumor agents or PDT/imaging. The combination of various treatment techniques may considerably improve the synergistic therapeutic effect of PTT and RNAi in the treatment of cancers.