Immunoengineering External Field Responsive Biomaterials for Tissue Repair and Regeneration.

Tissue defect repair is a dynamic process involving inflammation regulation, angiogenesis, organized extracellular matrix assembly, and immune microenvironment homeostasis. Its success critically depends on repair strategies with precise spatiotemporal control. External field-responsive biomaterials (EFRBs), which respond to optical, magnetic, electrical, ultrasonic, and thermal stimuli, have become a research focus in regenerative medicine due to their on-demand activation, unique (bio)physicochemical properties, and ability to modulate immune-related pathways. This review first outlines the dynamic biological requirements of tissue repair, including the immune microenvironment's role, and the core advantages of EFRBs. It then details the structural features and external field response mechanisms of various EFRBs-such as nanoparticles, scaffolds, hydrogels, and microneedles-and their regulatory effects on immune-related repair processes. Finally, it systematically summarizes recent advances in immunoengineering EFRBs for enhancing tissue repair and regeneration. This review thus aims to provide valuable insights for optimizing EFRB-based therapies and to inspire further breakthroughs in this evolving field.