cRGD-targeted dIR-Gd probe enables dual NIR/MRI imaging and photodynamic therapy for colorectal cancer.

Phototherapy offers promise for tumor treatment, yet faces significant clinical hurdles, primarily due to insufficient tumor specificity and the need for precise real-time guidance. Current methods often lack the ability for both accurate diagnosis and effective therapy in a single agent. This gap is particularly critical for colorectal cancer, where αvβ3 integrin is often overexpressed, presenting a valuable target for specific delivery. Developing multifunctional agents that combine imaging and therapy, especially with mitochondrial targeting for enhanced efficacy, is crucial for improving outcomes.

Researchers designed and synthesized a novel theranostic probe, dIR-Gd, composed of a NIR fluorophore (IR780), a cyclic peptide (cRGD) for tumor targeting, a sulfenic acid-reactive cyclohexanedione for covalent mitochondrial anchoring, and a MR imaging unit (DOTA-Gd3+). This dIR-Gd probe was engineered to self-assemble into nanoparticles in aqueous solution. The study then demonstrated its capabilities for sensitive NIR/MRI imaging and effective photodynamic therapy, leveraging its good tumor specificity and covalent immobilization within mitochondria, specifically targeting αvβ3 integrin-overexpressing colorectal tumors.