Nanomaterials Reshaping Tumor Metabolism: A New Frontier to Overcome T Cell Exhaustion.

Adoptive antitumor immunity ultimately fails because metabolically hostile tumor microenvironments (TME) drive T cells into a dysfunctional exhausted state that current checkpoint blockade only partially reverses. Crucially, the principal metabolic stresses - accumulation of lactate, lipids and adenosine, deprivation of glucose and amino acids, and hypoxia - do not act in isolation but form a densely cross-regulated network that progressively reinforces T cell exhaustion. This review synthesizes how each barrier arises and how they amplify one another, then maps nanomaterial-based countermeasures onto this network: catalytic nanomaterials that degrade lactate and adenosine, lipid-modulating and mitochondria-targeted formulations, amino-acid replenishment systems, and hypoxia-relieving designs that pair metabolic correction with checkpoint inhibition or photodynamic therapy. Particular attention is given to the design principles - tissue targeting, stimuli-responsive release and rational combination - that determine whether metabolic reprogramming yields durable restoration of T cell function rather than transient phenotypic rescue. Emerging preclinical evidence indicates that nanomaterial-mediated metabolic remodeling can convert the immunosuppressive TME into an immune-supportive niche and recover effector function of exhausted T cells. We further identify the key gaps that currently limit clinical translation: the absence of subset-level evaluation distinguishing reversible progenitor-like exhausted T cells from terminally exhausted cells, the lack of epigenetic endpoints such as histone lactylation, off-target metabolic suppression of T cells themselves, and the manufacturing and safety hurdles of clinical-grade nanomaterials. Resolving these issues would establish metabolic reprogramming as a credible frontier for next-generation cancer immunotherapy.