Advanced Coating Strategies for Immunomodulatory Biomaterials for Reconstructive Osteogenesis: Mitigating Foreign Body Reaction and Promoting Tissue Regeneration

Immune cells play a pivotal role in orchestrating tissue repair, executing functions such as debris clearance, extracellular matrix remodeling, and modulation of cytokine secretion profiles. However, when their activity is dysregulated or inadequately directed, these same processes can give rise to chronic inflammation and foreign body reactions (FBR), ultimately leading to fibrosis and compromised biomaterial performance. The immunological landscape following injury or biomaterial implantation is profoundly influenced by the physicochemical properties of material surfaces. By strategically tailoring these surface characteristics, it becomes possible to modulate immune cell responses—governing their adhesion, recruitment, proliferation, polarization, and cytokine expression patterns. This review elucidates the multifaceted roles of immune cells in tissue repair and their dynamic interactions with implanted biomaterials. It then explores how specific surface attributes—such as topography, chemistry, stiffness, and wettability—influence immune behavior. Particular emphasis is placed on recent advances in surface modification techniques aimed at engineering next-generation biomaterials that mitigate adverse immune responses while actively promoting regenerative healing. The review concludes by offering critical insights into the future of immunomodulatory biomaterial design, highlighting both emerging opportunities and persisting challenges in the field.