Hyperbranched 19F MRI Contrast Agents Integrated with Hydrophilic Fluorine Moiety and Targeting Peptide for Pancreatic Imaging

To achieve 19F magnetic resonance imaging (MRI) in vivo, a contrast agent (CA) with high fluorine content, long T2 relaxation time, and effective accumulation in the region of interest is required. Herein, we present a polyhedral oligomeric silsesquioxane (POSS)-based hyperbranched 19F MRI CA (POSS-CF3-Peptide), achieving pancreatic imaging by combining a phosphorylcholine fluorine tag and a pancreatic targeting peptide (Pra-PEG-Octa). The study demonstrates that the fluorine content of POSS-CF3-Peptide reaches 12.07%, and the T2 value is 752 ms at a concentration of 5 mg/mL, which effectively accumulates in the region of pancreas and affords clear 19F MRI visualization through intravenous injection. Furthermore, while exhibiting favorable 19F MRI property and pancreatic imaging, POSS-CF3-Peptide also exhibits good biocompatibility in vivo. This work exhibits that the synergistic integration of superhydrophilic hyperbranched scaffolds and targeting molecules can effectively overcome the delivery of traditional 19F MRI CAs and establish a structural design foundation for achieving high-density accumulation and precision in vivo imaging of challenging internal organs.