An extradomain-B fibronectin-targeted dextran-based CEST MRI probe for detecting pancreatic cancer.

A dextran-peptide conjugate was developed for magnetic resonance (MR) molecular imaging of pancreatic ductal adenocarcinoma (PDAC) through its overexpressed microenvironment biomarker, extradomain-B fibronectin (EDB-FN). This new agent consists of diamagnetic and biocompatible dextran and a targeting peptide. Dextrans can be directly detected by chemical exchange saturation transfer magnetic resonance imaging (LEST MRI) without the need for radionuclide or metallic labeling. In addition, large molecular weight dextran, dextran 10 (MW similar to 10 kDa), provides an approximately SO times higher sensitivity per molecule than a single glucose unit. The potential of this highly biocompatible diamagnetic probe is demonstrated in a murine syngeneic allograft PDAC tumor model. The biocompatibility and sensitivity of this new agent clearly show potential for a path to clinical translation.