Non-viral gene delivery for cancer immunotherapy

Recent decades have witnessed the revolutionary development of cancer immunotherapies, which boost cancer-specific immune responses for long-term tumor regression. However, immunotherapy still has limitations, including off-target side effects, long processing times and limited patient responses. These disadvantages of current immunotherapy are being addressed by improving our understanding of the immune system, as well as by establishing combinational approaches. Advanced biomaterials and gene delivery systems overcome some of these delivery issues, harnessing adverse effects and amplifying immunomodulatory effects, and are superior to standard formulations with respect to eliciting antitumor immunity. Nucleic acid-based nanostructures have diverse functions, ranging from gene expression and gene regulation to pro-inflammatory effects, as well as the ability to specifically bind different molecules. A brief overview is provided of the recent advances in the non-viral gene delivery methods that are being used to activate cancer-specific immune responses. Furthermore, the tumor microenvironment-responsive synergistic strategies that modulate the immune response by targeting various signaling pathways are discussed. Nanoparticle-based non-viral gene delivery strategies have great potential to be implemented in the clinic for cancer immunotherapy.