Peri-implantitis can lead to implant failure. In this study, curcumin (CUR) was modified onto the copper-bearing titanium alloy (Cu-Ti) with the assistance of polydopamine (PDA) in order to study the bone immune response and subsequent osteogenesis. FE-SEM, XPS and water contact angle were utilized to characterize the coating surface. Bone marrow mesenchymal stem cells (BMSCs) and macrophages were cultured separately and together onto the CUR modified Cu-Ti. Cell activity, expression of relative genes and proteins, cell migration ability, and fluorescence staining of cells were performed. CUR modification slightly increased the activation of M1-type and M2-type cells under physiological conditions. In the inflammation state, CUR inhibited the overexpression of M1 macrophages and induced M2-type differentiation. In addition, the modification itself could provoke the expression of osteoblastic-related genes of BMSCs, while promoting the osteogenic differentiation of BMSCs through the activation of macrophages in both physiological and inflammatory states. The BMSCs migration was increased, the expression of osteogenic-related genes and proteins was up-regulated, and alkaline phosphatase activity (ALP) was increased. Thus, the modification of CUR can promote the osteointegration effect of Cu-Ti by bone immunomodulation and may, in addition, improve the success rate of implants.
Keywords: bone immunoregulation; copper-bearing titanium; curcumin; dental implant; surface modification.