Proximity-regulating nanotechnology for tumor treatment.

Proximity is a prerequisite for initiating numerous physiological processes. The proximity of biomolecules triggers cellular signaling events such as activation, inhibition, internalization, and degradation. The proximity between organelles may induce lipid transfer and autophagy. Cell-cell proximity is essential for immune activation, suppression, or evasion. Herein, regulating the proximity among biological components represents a potential strategy for controlling the initiation or cessation of physiological processes. In recent years, strategies utilizing nanotechnology to regulate the proximity of biological components have garnered significant attention in tumor therapy. In this review, we summarize the application of proximity regulation strategies at molecular, organellar, and cellular levels in tumor treatment, discuss challenges in clinical translation, and outline future directions. We hope this paper inspires the development and clinical application of novel tumor treatment strategies.