Multifunctional Theranostic Nanoplatform Based on Fe-mTa₂O₅@CuS-ZnPc/PCM for Bimodal Imaging and Synergistically Enhanced Phototherapy

Abstract

Multifunctional nanotheranostic agent with high performance for tumor site-specific generation of singlet oxygen (¹O₂) as well as imaging-guidance is crucial to laser-mediated photodynamic therapy. Here, we introduced a versatile strategy to design a smart nanoplatform using phase change material (PCM) to encapsulate photosensitizer (zinc phthalocyanine, ZnPc) in copper sulfide loaded Fe-doped tantalum oxide (Fe-mTa₂O₅@CuS) nanoparticles. When irradiated by 808 nm laser, the PCM is melted due to the hyperthermia effect from CuS nanoparticles, inducing the release of ZnPc to produce toxic ¹O₂ triggered by 650 nm light with very low power density (5 mW/cm²). Then, the produced heat and toxic ¹O₂ can kill tumor cells in vitro and in vivo effectively. Furthermore, the special properties of Fe-mTa₂O₅ endow the nanoplatform with excellent computed tomography (CT) and T₁-weighted magnetic resonance imaging ( T₁-MRI) performance for guiding and real-time monitoring of therapeutic effect. This work presents a feasible way to design smart nanoplatform for controllable generation of heat and ¹O₂, achieving CT/ T₁-MRI dual-modal imaging-guided phototherapy.