Chiral Iron Oxide Supraparticles Enable Enantiomer‐Dependent Tumor‐Targeted Magnetic Resonance Imaging

Abstract The chemical, physical and biological effects of chiral nanomaterials have inspired general interest and demonstrated important advantages in fundamental science. Here, chiral iron oxide supraparticles (Fe 3 O 4 SPs) modified by chiral penicillamine (Pen) molecules with g ‐factor of ≈2 × 10 −3 at 415 nm are fabricated, and these SPs act as high‐quality magnetic resonance imaging (MRI) contrast agents. Therein, the transverse relaxation efficiency and T 2 ‐MRI results demonstrated chiral Fe 3 O 4 SPs have a r 2 relaxivity of 157.39 ± 2.34 mM −1 ·S −1 for D ‐Fe 3 O 4 SPs and 136.21 ± 1.26 mM −1 ·S −1 for L ‐Fe 3 O 4 SPs due to enhanced electronic transition dipole moment for D ‐Fe 3 O 4 SPs compared with L ‐Fe 3 O 4 SPs. The in vivo MRI results show that D ‐Fe 3 O 4 SPs exhibit two‐fold lower contrast ratio than L ‐Fe 3 O 4 SPs, which enhances targeted enrichment in tumor tissue, such as prostate cancer, melanoma and brain glioma tumors. Notably, it is found that D ‐Fe 3 O 4 SPs have 7.7‐fold higher affinity for the tumor cell surface receptor cluster‐of‐differentiation 47 (CD47) than L ‐Fe 3 O 4 SPs. These findings uncover that chiral Fe 3 O 4 SPs act as a highly effective MRI contrast agent for targeting and imaging broad tumors, thus accelerating the practical application of chiral nanomaterials and deepening the understanding of chirality in biological and non‐biological environments.