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

A dextran-peptide conjugate was developed for 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 (CEST) MRI without the need for radionuclide- or metallic labelling. In addition, large molecular weight dextran, dextran 10 (MW~ 10 kD), provides an approximately fifty 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.