Fig. 4

The effects of dendritic cells (DCs) in biomaterials-mediated bone repair and regeneration. The intrinsic physicochemical properties of biomaterials could modulate DCs polarization to influence bone healing and regeneration, such as surface chemistry, hydrophilicity, topography and spatial structures, roughness, and so on. Materials like pure titanium (PT) and sand-blasted, acid-etched titanium (SLA) surfaces promote DCs maturation, characterized by the upregulation of co-stimulatory molecules (e.g., CD40, CD80, CD86) and pro-inflammatory cytokines (e.g., IL-6, TNF-α), which drive immune activation and inflammation, potentially impairing bone healing. In contrast, modified surfaces such as modSLA or β-TCP induce a tolerogenic phenotype in DCs, marked by the downregulation of co-stimulatory molecules and the upregulation of anti-inflammatory cytokines (e.g., IL-10, TGF-β). These tolDCs foster a regulatory immune environment, enhancing osteoblast differentiation and supporting bone regeneration. mDCs mature dendritic cells, iDCs immature dendritic cells, tolDCs tolerogenic dendritic cells