Scheme 1. Schematic illustration of using a photoresponsive antibody–siRNA conjugate (PARC) for tumor-specific delivery of siPD-L1. Photoirradiation on tumors liberates siPD-L1 from PARC to silence intracellular PD-L1 expression in the cytoplasm, which combines with the αPD-L1-mediated blockade of membrane PD-L1 to boost anti-cancer immunotherapy.
