Transcytosis Mediated Deep Tumor Penetration for Enhanced Chemotherapy and Immune Activation of Pancreatic Cancer

Abstract The hyperproliferative tumor stroma of pancreatic ductal adenocarcinoma (PDAC) severely limits drug permeation and constructs an immunosuppressive microenvironment, causing resistance to chemotherapy and immunotherapy. Traditional nanomedicine mainly focuses on manipulating nanoparticles’ particle size or electrical characteristics to penetrate deep PDAC through the paracellular pathway, but the transcellular pathway is often ignored. Therefore, a versatile drug‐polymer conjugate PODEA‐Gem‐HMI is prepared and assembled into nanoparticles for the codelivery of chemotherapy drug gemcitabine and focal adhesion kinase (FAK) inhibitor defactinib. While sensing the mild acidity in the tumor microenvironment, the nanoparticle will disintegrate and release defactinib to modulate the tumor stroma. The PODEA block of the conjugate can bind with cell membranes reversibly and trigger adsorption‐mediated transcytosis (AMT) for promoted tumor penetration and cellular uptake. The internalized conjugates will release gemcitabine responding to the overexpressed glutathione (GSH) for enhanced chemotherapy, and PHMI can condensate the STING monomers for prolonged spontaneous immune stimulation.