A metal coordination polymer nanoparticle synergistically re-establishes acidosis and enhances chemodynamic therapy for Glioblastoma

Background

Chemodynamic therapy (CDT) has become increasingly important as a tumor treatment strategy, which relies on intracellular acid and hydrogen peroxide to kill tumor cells by generating hydroxyl radicals (·OH) through Fenton/Fenton-like reactions. However, the weakly alkaline intracellular environment considerably caused by the efflux of lactate and H⁺ from glioblastoma cells is not conducive to CDT performance. Intracellular acidification induced by inhibiting the transmembrane monocarboxylate transporter 4 (MCT4) can enhance the therapeutic efficacy of CDT. Existing approaches suffer from insufficient MCT4 inhibition, involve complex drug synthesis, and have many unsatisfactory side effects.

Methods

In this study, we constructed an anti-tumor nanoparticle formed by self-assembly driven by the coordination interaction of Fe³⁺ and α-cyano-4-hydroxycinnamate (CHC) to avoid safety issues posed by excessive modification. Fe-CHC nanoparticles were designed to decrease intracellular pH through inhibition of MCT4, which transports lactate/H⁺ to the extracellular space. The resulting intracellular accumulation of lactate and H⁺ led to fatal acidosis and promoted ·OH generated by Fenton/Fenton-like reactions with the presence of the Fe³⁺, thus enhancing CDT-induced tumor cell death.

Results

In vitro and in vivo results revealed that Fe-CHC exerted a significant synergistic anti-tumor effect by re-establishing acidosis and enhancing CDT in glioblastoma. Furthermore, the decreased H⁺outside the cells caused by the inhibition of lactate/H⁺ efflux hindered extracellular matrix degradation, thereby inhibiting tumor metastasis.

Conclusion

Fe-CHC is an effective anti-cancer agent against glioblastoma. This study provides valuable insights for developing acid-modulating anti-tumor nanoparticles, as well as enriching and optimizing the application of CDT in tumor therapy.

Statement of Significance

Our study pioneers the Fe-CHC nanoparticle, a metal-coordination polymer that targets MCT4 in glioblastoma cells to restore intracellular acidity and synergize with Fe³⁺ to boost chemodynamic therapy (CDT). Unlike other studies, Fe³⁺ and CHC work together to maximize the therapeutic potential and safety of Fe-CHC with minimal complexity. This innovative approach not only increased the production of reactive oxygen species within tumor cells, but also hindered tumor metastasis. Our work has important scientific implications for tumor microenvironment regulation and the application of CDT, and will provide a promising pathway for the treatment of aggressive cancers and attract a wide audience through its scientific implications.