Facile Synthesis of Manganese Tellurite Nanoparticles for Magnetic Resonance Imaging‐Guided Photothermal Therapy

Abstract In this study, manganese tellurite (MnTeO₃) nanoparticles are developed as theranostic agents for magnetic resonance imaging (MRI)‐guided photothermal therapy of tumor. MnTeO₃ nanoparticles are synthesized via a simple one‐step method. The as‐synthesized MnTeO₃ nanoparticles with uniform size show good biocompatibility. In particular, MnTeO₃ nanoparticles exhibit a high photothermal conversion efficiency (η = 26.3%), which is higher than that of gold nanorods. Moreover, MnTeO₃ nanoparticles also have high MRI performance. The longitudinal relaxivity (r₁) value of MnTeO₃ nanoparticles is determined to be 8.08 ± 0.2 mm⁻¹ s⁻¹, which is higher than that of clinically approved T₁‐contrast agents Gd‐DTPA (4.49 ± 0.1 mm⁻¹ s⁻¹). The subsequent MnTeO₃ nanoparticles‐mediated photothermal therapy displays a highly efficient ablation of tumor cells both in vitro and in vivo with negligible toxicity. It is demonstrated that MnTeO₃ nanoparticles can serve as promising theranostic agents with great potentials for MRI‐guided photothermal therapy.