来源：ACS Publications
Monodisperse oxide nanoparticles have attracted attention for biomedical applications. However, conventional synthetic methods often provide limited control over particle size, morphology, and polydispersity. Herein, we report a bottom-up strategy for synthesizing hollow rare-earth silicate nanospheres based on the Kirkendall effect. The addition of an optimized amount of 1-propanol to the reaction medium altered the dielectric constant and surface tension, thereby increasing the nucleation rate and reducing the precursor size. During high-temperature treatment, unequal interdiffusion of rare-earth and silicon atoms across the phase interface induced the Kirkendall effect and generated internal voids approximately 50 nm in size for drug loading. DOX-loaded nanospheres exhibited acid-responsive release and cytotoxicity, whereas RB-loaded nanospheres generated singlet oxygen under X-ray irradiation and induced cell death. These findings demonstrate the potential of hollow rare-earth silicate nanospheres as platforms for drug delivery and X-ray-induced photodynamic therapy.