Click chemistry-enabled lanthanide oxide nanoparticle: innovations in biomedical diagnostics and therapy

Several lanthanide, such as europium, gadolinium, terbium, dysprosium, and holmium, is widely explored as contrast agents in Magnetic Resonance Imaging due to the unique magnetic properties. The strong paramagnetic moment characteristic is derived from the spin-orbital motion of the 4f electrons to reduce transverse (T 1 ) and longitudinal (T 2 ) relaxation times. Lanthanide oxide nanoparticle have gained significant attention as contrast agents due to the advantages such as reduced toxicity compared to chelate-based agents, improved stability, prolonged circulation time in the bloodstream, and tunable surface properties for biocompatibility and targeting. In general, click chemistry offers great potential in the development of more specific and effective cancer diagnostics and therapies. It allows precise and efficient conjugation of lanthanide chelates to biomolecules, therapeutic agents, or targeting ligands under mild and biocompatible conditions. Through this approach, lanthanide-based contrast agents can be combined with therapeutic functionalities to create theranostic agents that both image and treat disease. In this review, we explore how lanthanide oxide nanoparticles modified click chemistry can be utilized in medicine. The primary focus is on the material's potential as an MRI contrast agent for diagnosis and its role in cancer treatment.