Size and Charge Dual‐Switchable Nanoparticles for Achieving Chemosensitization and Immune Infiltration against Pancreatic Ductal Adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDAC), one of the most challenging cancers, is uniquely characterized by a biological barrier composed of multiple components in the extracellular matrix, preventing penetration of chemotherapeutic agents and hindering clinical drug treatment. Collagen I arrangement is critical. In this study, gemcitabine is chosen as the chemotherapeutic agent and dasatinib as the collagen‐I‐disrupting agent. When collagen I arrangement is disrupted, not only the chemotherapeutic drug enters the tumor area better, but the infiltration of CD8 + T cells into the tumor also increases. Therefore, a hypoxia‐responsive linker‐crosslinked polymer, DGD/L@GBI, is designed, which can be simultaneously loaded with two therapeutic agents, gemcitabine and dasatinib. The polymer is encapsulated by nucleic acid aptamers that target the PDAC stromal microenvironment and shield the surface. The aptamer is removed upon arrival at the PDAC hypoxic microenvironment, exposing the positively charged core to achieve charge reversal. Particle size transformation is achieved using linkers that respond to a hypoxic microenvironment. Increased intratumoral penetration is achieved using the dual transformation capabilities of the formulation. Pairing these two agents can result in a powerful efficacy in chemotherapy sensitization and immune infiltration.