Fig. 2

Targeting immunomodulators to immune cells in tumor microenvironment (TME). a Strategies for the application of NPs in immune checkpoint blockade therapy: NP-encapsulated immune checkpoint inhibitors and PD-L1 siRNA (Node 1 and 2), NP-encapsulated different drugs combined with immune checkpoint inhibitors (Node 3 and 4). The particles carried the target modulator, which further targeted the epitopes on immune cells, and direct or indirect antitumor action. b NPs extravasate into the tumor stroma through the fenestrations of the angiogenic vasculature, which can be enhanced by the EPR effect. c NPs have ability to carry one or more therapeutic agent to modulate T cells activation. Upper: Category of NP assembly; Lower: Different therapeutic payload