High-Specificity In Vivo Tumor Imaging Using Bioorthogonal NIR-IIb Nanoparticles.

Lanthanide-based NIR-IIb nanoprobes are ideal for in vivo imaging. However, existing NIR-IIb nanoprobes often suffer from low tumor-targeting specificity, limiting their widespread use. Here the application of bioorthogonal nanoprobes with high tumor-targeting specificity for in vivo NIR-IIb luminescence imaging and magnetic resonance imaging (MRI) is reported. These dual-modality nanoprobes can enhance NIR-IIb emission by 20-fold and MRI signal by twofold, compared with non-bioorthogonal nanoprobes in murine subcutaneous tumors. Moreover, these bioorthogonal probes enable orthotopic brain tumor imaging. Implementation of bio-orthogonal chemistry significantly reduces the nanoprobe dose and hence cytotoxicity, providing a paradigm for real-time in vivo visualization of tumors.