Nanosomal Irinotecan Targeting Pancreatic Cancer Cell Surface Neuraminidase-1 Sialidase.

Pancreatic ductal adenocarcinoma (PDAC) is an increasing incidence and is the deadliest cancer. Most pancreatic cancer patients present with nonspecific symptoms at an advanced disease stage that is not amenable to curative surgery. Therapies by immune checkpoint inhibitors have proven difficult in the patients with PDAC. It is communicated that cell surface neuraminidase-1 (Neu-1) is a highly potential target molecule for nanomedicine to improve the therapeutic efficacy and safety of the present first-line therapies in patients with advanced PDAC. Nanosomes composed of an inorganic core and antiadhesive shell of phospholipid monolayer enable active delivery of irinotecan into intracellular space by targeting Neu-1. Nanosomal irinotecan is endocytosed efficiently and exhibits synergistically enhanced inhibitory effects on the growth of Panc-1 cells in vitro (IC50 = 8.07 nm) when displayed with an irreversible-mechanism based Neu-1 inhibitor that inactivates nucleophiles of Neu-1 by a covalent bond formation. Strikingly, in vivo antitumor effects of nanosomal irinotecan revealed that tumor growth in Panc-1 xenograft model is inhibited completely by injection at a dose of 5 mg kg-1 six times at 4-day intervals without body weight loss. The preliminary results provide evidence that targeting Neu-1 by nanomedicine is a promising drug delivery strategy to a desired chemotherapy in the patients with advanced PDAC.