Combining treatment and diagnosis, called theranostics, which is achieved within single nanoparticle is an ultimate goal of many studies. Herein, we developed a new nanotheranostic agent − Nd³⁺-sensitized upconversion nanoparticles core for dual modal imaging (i.e., upconversion luminescence imaging and magnetic resonance imaging) and antimony nanoshell for photothermal therapy (PTT). The core-shell-shell upconversion nanoparticles (NaYF₄:Yb,Er@NaYF₄:Yb,Nd@NaGdF₄:Nd, named as UCNP) were firstly synthesized using thermal decomposition method and then were coated by antimony shell over the surface of UCNP using simple cost and time effective new method. Furthermore, the surface of UCNP@Sb nanostructures was modified with DSPE-PEG in order to enhance the water solubility and biocompatibility. The final nanotheranostic agent, named as UCNP@Sb-PEG, exhibits very low toxicity, good biocompatibility, very good photothermal therapeutic effect, and efficient upconversion luminescence (UCL) imaging of HeLa cells under only one laser (808 nm) irradiation. The antimony shell is quenching the upconversion emission in pristine nanotheranostic agent, but interestingly, the UCL intensity of the agent recovers progressively under 808 nm laser irradiation due to light induced degradability of antimony shell. Besides, high longitudinal relaxivity (r₁) obtained from the experiment approves excellent potential of the nanotheranostic agent for T₁-weighted magnetic resonance imaging application.

将治疗和诊断相结合，称为治疗诊断学，在单个纳米颗粒内实现是许多研究的最终目标。在此，我们开发了一种用于双模态成像（即上转换发光成像和磁共振成像）的新型纳米治疗剂-Nd ^{3+敏化上转换纳米粒子核心和用于光热治疗（PTT）的锑纳米壳。}核-壳-壳上转换纳米粒子(NaYF ₄ :Yb,Er@NaYF ₄ :Yb,Nd@NaGdF ₄:Nd, 命名为 UCNP) 首先采用热分解法合成，然后使用简单的成本和时间有效的新方法在 UCNP 表面涂上锑壳。此外，UCNP@Sb纳米结构的表面用DSPE-PEG修饰，以提高水溶性和生物相容性。最终的纳米治疗剂，命名为 UCNP@Sb-PEG，仅在一次激光（808 nm）照射下就表现出极低的毒性、良好的生物相容性、非常好的光热治疗效果和高效的上转换发光（UCL）成像。锑壳正在淬灭原始纳米治疗剂中的上转换发射，但有趣的是，由于锑壳的光诱导降解性，该试剂的 UCL 强度在 808 nm 激光照射下逐渐恢复。除了，r ₁ ) 从实验中获得，证明了纳米治疗剂在T ₁加权磁共振成像应用中的巨大潜力。