Nanoscale delivery systems for cancer immunotherapy

Increased understanding of tumor immunology has prompted rapid development of cancer immunotherapy in the past few years. The recent clinical success of immunotherapeutic approaches, such as immune checkpoint blockade and chimeric antigen receptor T cells, demonstrates their potential as a cancer terminator. Nevertheless, strategies to improve the overall efficiency and to reduce the side effects of immunotherapy are highly demanded. Nano-delivery systems hold great promise in biomedical applications due to their unique physiochemical properties and advantages in efficient tissue-specific delivery, enhanced cellular uptake and responsiveness to physiological and environmental stimuli. Immuno-nanomedicine opens a new field in cancer treatment and has attracted broad interest. In this review, we present recent advances in the field of cancer immunotherapy and focus on the nanocarrier-mediated delivery of immunomodulators as well as manipulation of immune cells. Applications of various types of nanomaterials (inorganic, polymers, liposomes, DNA-based, biomimetic and bio-derived nanoparticles) are summarized. Challenges and opportunities of nanovehicles in cancer immuno-oncology are also discussed.