Biomimetic mesoporous polydopamine nanoparticles for MRI-guided photothermal-enhanced synergistic cascade chemodynamic cancer therapy

Traditional anticancer treatments fail to significantly improve prognoses, and exploration of novel promising therapeutic modalities is urgently needed. In this study, multifunctional mesoporous polydopamine nanoparticles (Pt@MPDA/GOx/Fe³⁺ NPs) loaded with glucose oxidase (GOx), Fe ions and ultrasmall Pt nanoparticles (NPs) were prepared for magnetic resonance imaging (MRI)-guided photothermal therapy (PTT)-enhanced chemodynamic therapy (CDT). The oxidation of intratumoral glucose to H₂O₂ and GOx induced an H₂O₂-rich microenvironment, and then elevated H₂O₂ was catalyzed into highly cytotoxic ·OH by Fe³⁺ via a Fenton reaction for CDT to induce cancer cell death efficiently. Notably, the heat generated by MPDA NPs under laser irradiation offered a moderate PTT to cascade the CDT effect. Moreover, Pt NPs can oxidize H₂O₂ to yield O₂, which in turn accelerates the catalytic process of GOx to increase the efficiency of CDT. Meanwhile, in the high oxidation environment of tumor cells, Pt NPs are oxidized into Pt²⁺ to achieve a tumor chemotherapy effect. In addition, chelated Fe³⁺ endows the system with an MRI-visible function to monitor the treatment efficacy. In conclusion, this study provides a novel MRI-guided PTT-enhanced CDT synergistic nanomedicine platform for cancer therapy.