Macrophage-associated biocompatibility of titanium revealed by analyzing foreign body reaction at bone-implant interface.

Purpose: Titanium implants are widely used to replace pathological joints, bones, and teeth, with successful engraftment requiring osteoblast attachment to the metal surface for bone regeneration. However, the immune response at the bone-implant interface remains unclear, and few studies have examined why titanium elicits a reduced foreign-body reaction (FBR) compared to other metals. This study aimed to elucidate the mechanism underlying titanium biocompatibility by characterizing the immune response at the bone-implant interface in a rat model.