Erlotinib Engineering Programs Tumor Targeting in an Atomically Precise Au8 Cluster

Abstract Atomically precise metal clusters hold great promise for cancer theranostics, yet current strategies for introducing tumor-targeting functionality often compromise their structural precision. Herein, an erlotinib (Er)-functionalized gold cluster, Au8-Er, is constructed through ligand engineering for targeted non-small-cell lung cancer (NSCLC) theranostics. The Er ligands endow Au8-Er with high affinity toward the epidermal growth factor receptor (EGFR), enabling selective tumor targeting and preferential accumulation at lung tumor sites. Under the glutathione-rich tumor microenvironment, Au8-Er releases Er to achieve chemotherapy. Simultaneously, the cluster exhibits strong X-ray attenuation and oxygen-sensitive phosphorescence, allowing it to function as both an X-ray scintillator and a photosensitizer for efficient X-ray-induced photodynamic therapy (X-PDT) under low-dose irradiation. Moreover, its X-ray-excited luminescence enables high-contrast imaging. The synergistic integration of targeted chemotherapy, X-PDT, and imaging within a structurally precise nanoplatform results in enhanced therapeutic efficacy against NSCLC. This work highlights ligand engineering as an effective strategy for imparting biological functionality to atomically precise metal clusters and advances their application in precision cancer theranostics.