Abstract
Molecular imaging of cancer biomarkers is critical for non-invasive accurate cancer detection and risk-stratification in precision healthcare. A peptide-targeted tri-gadolinium nitride metallofullerene, ZD2-Gd3N@C80, is synthesised for sensitive molecular magnetic resonance imaging of extradomain-B fibronectin in aggressive tumours. ZD2-Gd3N@C80 has superior r 1 and r 2 relaxivities of 223.8 and 344.7 mM-1 s-1 (1.5 T), respectively. It generates prominent contrast enhancement in aggressive MDA-MB-231 triple negative breast cancer in mice at a low dose (1.7 µmol kg-1, 1 T), but not in oestrogen receptor-positive MCF-7 tumours. Strong tumour contrast enhancement is consistently observed in other triple negative breast cancer models, but not in low-risk slow-growing tumours. The dose of the contrast agent for effective molecular MRI is only slightly lower than that of ZD2-Cy5.5 (0.5 µmol kg-1) in fluorescence imaging. These results demonstrate that high-sensitivity molecular magnetic resonance imaging with ZD2-Gd3N@C80 may provide accurate detection and risk-stratification of high-risk tumours for precision healthcare of breast cancer.Molecular MRI is a powerful clinical tool for non-invasive detection of cancer biomarkers. Here, the authors develop a targeted peptide gadofullerene contrast agent that can sensitively distinguish between breast cancers of different aggressiveness.