Mesoporous polydopamine composite nanoparticles for multimodal therapy based on disrupting the redox homeostasis within tumor cells.

Developing multimodal combination therapy strategies to disrupt the redox homeostasis within tumor cells is currently an important approach in cancer treatment. In this study, we designed and prepared multifunctional composite nanoparticles MPDA-PEG@MnO2@2-DG (MPPMD NPs) utilizing mesoporous polydopamine nanoparticles (MPDA NPs) as carriers. These carriers were coated with polyethylene glycol (PEG), and manganese dioxide (MnO2) and loaded with 2-deoxy-d-glucose (2-DG). Studies on mechanism revealed that upon accumulation in tumor cells via in situ injection, MnO2 can react with overexpressed H2O2 to generate Mn2+, O2, and toxic OH. Additionally, MnO2 undergoes an oxidation-reduction reaction (redox) with glutathione (GSH), consuming GSH and generating Mn2+. The resulting Mn2+ further participates in Fenton-like reactions with overexpressed H2O2 within the tumor. Furthermore, under 808 nm laser, MPPMD NPs facilitate photothermal therapy (PTT), promoting the generation of reactive oxygen species (ROS), inducing oxidative stress, and reducing the adenosine triphosphate (ATP) level. Concurrently, the 2-DG loaded by MPPMD NPs disguised as glucose disrupts the glycolysis process, inhibiting ATP production, and effectively inducing tumor starvation therapy (ST). By leveraging the multifunctionality of MPPMD NPs, this work realized the disruption of redox homeostasis within tumor cells, providing potential strategies for multimodal tumor treatment.