Schematic illustration of the nanostructure designed for cancer immunotherapy. (A) Preparation of the PDL1-NP-FEXO. Thiol-modified PD-L1 aptamer was conjugated to the amino-groups of albumin via SMCC. FEXO was encapsulated into aptamer-modified albumin nanoparticle to form the PDL1-NP-FEXO. (B) The potential mechanism of PDL1-NP-FEXO for cancer therapy. PDL1-NP-FEXO binds to the PD-L1 expressed on the surface of tumor cells. FEXO blocks the interaction of HRH1 and histamine, reducing number of M2 macrophages in tumor tissue. PD-L1 aptamers on the nanostructure block the PD-1/PD-L1 interaction, boosting the antitumor response of T cells. BSA: bovine serum albumin, SMCC: Sulfosuccinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate, FEXO: fexofenadine, Mφ: macrophage, HRH1: histamine receptor H1, TIME: tumor immune microenvironment.