Lanthanide-Cyclen-Camptothecin Nanocomposites for Cancer Theranostics Guided by Near-Infrared and Magnetic Resonance Imaging

We have devised a molecular-to-micellar strategy to incorporate a lanthanide nanoplatform for the delivery of an anticancer drug that simultaneously offers hybrid near-infrared (NIR) and magnetic resonance imaging (MRI) capabilities with defined lanthanide(III) ratio control. This cancer-selective lanthanide-based self-assembled nanocomposite (LnNPs) has been synthesized by conjugating lanthanide-cyclen complexes (cycLn) with a well-known drug-camptothecin (CPT) through a redox-sensitive disulfide bond (-ss-). By accurately controlling the ratio of Gd(III) and Yb(III) complexes, we prepared hybrid nanoparticles (Gd/YbNPs) with both NIR and MR imaging properties. The enhanced stability at ultralow critical aggregation concentrations (CACs), simultaneous optical and MR imaging, improved delivery/chemotherapeutic efficiency, and cancer cell selectivity of such nanomicellar theranostic prodrugs in vitro and in vivo have thus been achieved and validated. The work provides a blueprint combining a stimuli-activated NIR luminescence and real-time MR imaging into a safe and biocompatible nanoplatform for selective cancer treatment.