Clinical Applications and Future Prospects of Metallic Nanoparticles in Diagnosis and Therapy.

Metallic nanoparticles (MNPs) have emerged as versatile platforms for addressing unmet clinical needs in diagnosis, therapy, and theranostics. This review synthesizes recent advances in the clinical application of iron-, gold-, hafnium-, gadolinium-, silver-, copper-, titanium-, and zinc-based nanoparticles across oncology, infection control, biomedical coatings, and diagnostic imaging. In oncology, superparamagnetic iron oxide nanoparticles (SPIONs) have demonstrated a median overall survival of 13.4 months in patients with recurrent glioblastoma and achieved intratumoral temperatures of 42-48.5 °C during magnetic hyperthermia. Gold-silica nano shells generated tumor-free ablation zones in up to 87.5% of prostate lesions, with oncologic success reported in 73% of treated patients. CYT-6091, a ~27 nm PEGylated gold nanoparticle conjugated with TNF-α, enabled systemic delivery of this cytokine without inducing severe hypotension, showing a substantially improved safety profile compared with free TNF-α. In antimicrobial applications, Nano Silver Fluoride reduced dentin caries progression by more than 30% compared with controls, while copper nanoparticle-reinforced universal adhesives preserved mechanical performance and retention rates over 48 months. Collectively, these findings highlight the capacity of MNPs to integrate diagnostic and therapeutic functions, including MRI/CT contrast enhancement, magnetic hyperthermia, photothermal and photodynamic therapies, and gene delivery. Despite significant progress, challenges related to heterogeneous biodistribution, long-term toxicity, and regulatory approval remain, emphasizing the need for the development of safer and more efficient metallic nanomedicines aligned with emerging clinical demands in personalized medicine.