Functional Nanomaterials Optimized to Circumvent Tumor Immunological Tolerance

Advances in cancer immunology have revealed that immunological tolerance, which is characterized by low immunogenicity, insufficient antigen presentation, and low T lymphocyte infiltration, increases the expression of inhibitory receptors and cytokines in tumors. These features make it possible for tumor cells to easily escape attack by immune cells. Nanomaterials, with unique properties such as ultrasmall size, unique surface characteristics, and multivalent effects, have attracted an increasing amount of attention in the regulation of the immunological microenvironment of tumors. In this review, the use of functional nanomaterials to reverse immunological tolerance in tumors is examined, including the use of nanomaterials for efficient cancer vaccines, checkpoint blockade delivery, cytokine delivery, artificial antigen presentation cells, and adoptive cell therapy. The benefits and challenges of using nanomaterials to circumvent the immunological tolerance of tumors are also discussed.