Advances in Research on Tumor Microenvironment-responsive Nano Drug Delivery Systems for Tumor Immunotherapy

Great progress on cancer immunotherapy has been made in the past few decades, but unsatisfactory patient response rate and potential immune related adverse events are still the main clinical challenges. Nano drugs delivery systems (NDDSs) have unique advantages in tumor treatment. Based on the characteristics of tumor microenvironment(TME) such as hypoxia, weak acidity and abnormal expression of protease, researchers have designed stimulus-responsive NDDSs, which have been widely studied to improve the effectiveness of anti-tumor immune response and to reduce immune-related side effects. This article introduces the advances in research on tumor microenvironment-responsive NDDSs used for tumor immunotherapy, and discusses the application prospect and challenges of this type of drug delivery systems.