Advances in metal-based nano drugs and diagnostic probes for tumor

Tumors, particularly malignant ones, seriously impact human health. Numerous studies have demonstrated the exceptional potential of metal-based nanosystems, both as drugs and drug delivery systems (DDS), in killing tumor cells in combination with chemotherapy, phototherapy, immunotherapy, radiotherapy, and other treatments, resulting in considerable therapeutic effects against tumors. Furthermore, metal-based fluorescent probes can diagnose tumors by detecting tumor-related biomarkers, and contrast agents (CAs) can diagnose tumors by contrasting imaging between normal and tumor tissues. These two types of diagnostic probes play a critical role in tumor prevention and monitoring of clinical treatment effects. This review focuses on recent advances in metal-based micelles, liposomes, nanoparticles (NPs), nanosheets (NSs), metal-phenolic networks (MPNs), and metal-organic frameworks (MOFs) nanosystems, as well as their applications as drugs, DDS, and probes over the past five years. This review also highlights the latest research advances in their use as fluorescence diagnostic probes and magnetic resonance imaging (MRI) CAs in tumors. Furthermore, the toxicity mechanism of metal-based nanosystems is analyzed, and the strategies to reduce their systemic toxicity are proposed. Finally, this review includes a conclusion and a prospect for the future clinical translation of metal-based nanosystems in the diagnosis and treatment of tumors.