Immunomodulatory Biomaterials for Bone and Soft Tissue Chronic Inflammation Diseases

Chronic inflammatory diseases of bone and soft tissue pose significant clinical challenges due to their complex pathogenesis and the limitations of conventional therapies, which often fail to address immune microenvironment dysregulation. This review explores the pivotal roles of key immune cells (including mast cells, macrophages, neutrophils, T cells, B cells, and dendritic cells) in driving inflammatory progression and tissue damage through dynamic cellular interactions and cytokine networks. It systematically analyzes the molecular and structural foundations of immunomodulatory biomaterials, such as nanoparticles, hydrogels, and scaffolds, which offer precise spatiotemporal control over immune cell phenotypes and inflammatory mediators. By integrating advances in immunology and materials science, this review highlights how surface functionalization, controlled drug release, and composite material strategies synergistically restore immune homeostasis and promote tissue regeneration. Studies across common chronic inflammatory diseases (e.g., osteoporosis, osteomyelitis, osteoarthritis, diabetic wounds, spinal cord injury, and intervertebral disc degeneration) demonstrate the therapeutic potential of biomaterial-mediated immunomodulation, such as nanoparticle-driven macrophage polarization, cytokine-loaded hydrogel-mediated immune cell balance, and scaffold-guided immune cell recruitment. Challenges in clinical translation, including material biocompatibility and multicomponent synergy, are critically addressed. This review underscores the transformative potential of immunomodulatory biomaterials as next-generation precision therapies to overcome therapeutic bottlenecks in chronic inflammatory diseases.