Abstract: Objective: To explore the effect and mechanism of static magnetic field on osteoblasts and macrophages on pure titanium surface. Methods: Under the static magnetic fields of 0 mT and 100 mT, cells were cultured on the surface of tissue culture well plates and sandblasting and acid etching (SLA-treated) titanium sheets, respectively. CCK-8 method was used to detect the effect of static magnetic field on the viability of osteoblasts and macrophages. Cytoskeleton fluorescence staining was used to detect the morphological changes of osteoblasts and macrophages under static magnetic field. Immunofluorescence staining was used to detect the expression of runt-related transcription factor 2 (Runx2), protein in osteoblasts under static magnetic field. The expression of osteogenesis-related genes in osteoblasts and immune-related genes in macrophages was detected by quantitative real-time fluorescence quantitative PCR (RT-qPCR). The expression levels of polarization-related proteins CD86 and CD206 in macrophages were detected by flow cytometry. Results: The static magnetic field of 100 mT could effectively promote the proliferation of osteoblasts on the titanium sheets, promote the expression of osteogenesis-related genes alkaline phosphatase (ALP), collagen type Ⅰ (COL-1), Runx2, and osteoprotegerin (OPG), and enhance the synthesis of osteogenesis-related protein Runx2. The static magnetic field of 100mT could promote the proliferation of macrophages, promote the polarization of macrophages to M1 type on the 3rd day, and inhibit the expression of inflammation-related genes tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) on the 7th day. Conclusion: Static magnetic field has the ability to promote the proliferation and mineralization of osteoblasts on the SLA-treated titanium sheets, and to promote the transformation of macrophages from pro-inflammatory to anti-inflammatory on the titanium sheets.

Key words: static magnetic field, titanium, osteogenesis, immune