A Multifunctional Nanosystem Catalyzed by Cascading Natural Glucose Oxidase and Fe₃O₄ Nanozymes for Synergistic Chemodynamic and Photodynamic Cancer Therapy

The significance of the tumor microenvironment (TME) in tumor initiation and progression is increasingly acknowledged. Conventional therapeutic approaches face limitations within the complex TME, including the restrictions imposed by hypoxia on photodynamic therapy (PDT) and the deficiency of endogenous H₂O₂ affecting chemodynamic therapy (CDT). In response to the TME's characteristics of high metabolism, hypoxia, and weak acidity, a multifunctional nanosystem MNPs/GOD@CS/IR820, which synergistically integrates CDT and PDT, has been developed. This system can actively accumulate at tumor sites under an external magnetic field and release active components in response to the weakly acidic TME. It mitigates the limitations imposed by hypoxia and endogenous H₂O₂ deficiency on PDT and CDT, respectively, thereby enabling synergistic treatment. Additionally, the system's multimodal imaging capabilities facilitate precise tumor localization and real-time, non-invasive in vivo assessment via fluorescence imaging and MRI. In vitro and in vivo evaluations demonstrate significant antitumor efficacy, effectively inhibiting tumor growth and improving survival rates. By comprehensively addressing the challenges posed by the complex TME and enhancing real-time monitoring capabilities, our nanosystem paves the way for personalized and precise cancer treatment. STATEMENT OF SIGNIFICANCE: This study introduces an innovative MNPs/GOD@CS/IR820 nanosystem that represents a significant advancement in cancer nanomedicine by addressing critical limitations of conventional photodynamic therapy (PDT), particularly in hypoxic tumor microenvironments. By synergistically integrating chemodynamic therapy (CDT) with PDT and incorporating MRI and fluorescence dual-modal imaging capabilities, this multifunctional platform offers enhanced therapeutic efficacy and real-time monitoring. The system's ability to generate oxygen in situ overcomes hypoxia-induced limitations, while its multimodal mechanism of action induces tumor cell apoptosis through multiple pathways. In vitro and in vivo studies demonstrate remarkable antitumor efficacy across diverse cancer types, significantly inhibiting tumor growth and improving survival rates. This comprehensive approach to cancer diagnosis and treatment not only advances precision medicine for targeted, multimodal cancer management but also provides a promising foundation for future clinical applications, potentially transforming cancer treatment strategies and improving patient outcomes.