Redox modulation of antitumor immunity via nanomedicine

Redox imbalance is a defining feature of the tumor microenvironment (TME). Tumor cells adapt to this oxidative pressure through robust antioxidant pathways, whereas immune cells are easily impaired, leading to poor antigen presentation, compromised T-cell dysfunction, and an immunosuppressive milieu. These redox disturbances affect nearly every step of the cancer-immunity cycle. Targeting the redox balance is thus a critical objective. However, this therapeutic avenue is fraught with challenges. The complexity and dynamic characteristics of redox regulation pose major obstacles to achieving precise modulation in the TME. Nanomedicine offers practical strategies to modulate redox dynamics, either by amplifying oxidative stress or reinforcing antioxidant capacity. This review provides a critical overview of the biological mechanisms underlying redox dysregulation in the TME, highlights nanomedicine-based interventions for precise redox modulation, and evaluates their strategic applications across the cancer-immunity cycle. Furthermore, we synthesize essential design principles to navigate the redox paradox, ultimately discussing future perspectives for overcoming translational barriers in redox-based cancer immunotherapy.