Synthesis of lutetium phosphate–apoferritin core–shell nanoparticles for potential applications in radioimmunoimaging and radioimmunotherapy of cancers

We report a novel approach for synthesizing LuPO4–apoferritin core–shell nanoparticles based on an apoferritin template. To prepare the nanoparticle, we used non-radioactive lutetium as a model target or surrogate for radiolutetium (177Lu). The central cavity, multi-channel structure, and chemical properties of apoferritin are well-suited for sequentially diffusing lutetium and phosphate ions into the cavity, resulting in a stable core–shell composite. We characterized the synthesized LuPO4–apoferritin nanoparticle using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). We found that LuPO4 formed inside the cavity of apoferritin with an 8 nm diameter. We tested the pre-targeting capability of biotin-modified lutetium–apoferritin nanoparticle using streptavidin-modified magnetic beads and streptavidin-modified fluorescein isothiocyanate (FITC) tracer. This paper presents a simple, fast, and efficient method for synthesizing LuPO4–apoferritin nanoparticle for potential applications in radioimmunotherapy and radioimmunoimaging of cancer.