Development of nano-immunotherapy for cancer treatment: achievements and scopes

Background Cancer immunotherapy, which activates the immune system of the human body to fight cancer cells, is a new paradigm for cancer treatment that follows first-generation chemotherapeutics and second-generation cancer-targeting agents. Cancer patients who respond to immuno-oncology drugs can experience continuous anticancer effects because cancer immunotherapy uses the memory and adaptiveness of the human immune system. Immunotherapeutics such as immune checkpoint inhibitors, immune cell therapies, anticancer vaccines, and antibody-drug conjugates are changing the present cancer treatment landscape owing to their anticancer efficacy and improvement in the survival rate of cancer patients. However, the clinical use of cancer immunotherapy has limitations, such as variation in the therapeutic response rate between patients and side effects including cytokine storm syndrome and immunosuppressive barriers. Area covered In this review, we describe cancer immunotherapy related to the tumor immune microenvironment and discuss the achievements and scope of nano-immunotherapy for cancer treatment. Expert opinion Tumors have complex characteristics, and immune cell types are diverse. The recent exploration for overcoming the limitations of cancer immunotherapy has paved the way towards the use of nanoparticles for the delivery of immunotherapeutics and/or anticancer agents near the tumor tissue, as well as for immuno-bioimaging.