Magnesium promotes implant osseointegration by regulating LepR + stem cells

Background Homing and differentiation of stem cells is a necessary step in achieving implant osseointegration. However, the specific role and mechanism about stem cells in the osseointegration process were rarely reported. Rencently, LepR ⁺ cells were identified as crucial skeletal stem cells in the long bone and alveolar bone, which participated homeostasis maintenance and damage repair. As one of the indispensable trace elements in the human body, Mg ²⁺ were proved to promote vascularized bone regeneration. Here, by combining tissue clearing technique and immunofluorescent mice, we proved that Mg ²⁺ promoted implant osseointegration by regulating LepR ⁺ stem cells aggregation and differentiation at the implant-bone interface in vivo and provided a new perspective to promote the study of implant research. Purpose The aim of the study was to explore the effects of Mg ²⁺ in promoting implant osseointegration in the alveolar bone. Methods The cell proliferation and osteogenic differentiation were performed to screening the optimal Mg ²⁺ concentration for MC3T3-E1 osteoblasts. Then the optimal Mg ²⁺ was loaded on a self-designed SLA implant hydrothermally. Characterization and bio-compatibility of materials were detected. In vivo, combining the PEGASOS with LepR-Cre;tdTomato;Col2.3-GFP mice, we traced the LepR positive ( LepR ⁺ ) stem cells aggregation and differentiation at the implant-bone interface. Results 5mM Mg ²⁺ was screened to be the optimal concentration for MC3T3-E1 osteoblasts. EDS and XRF proved that Mg ²⁺ was successfully corroborated onto the implants. Further detection confirmed the better stretching and proliferatio of Mg-coating implants. 3-D imaging revealed that Mg-coating implants facilitated LepR ⁺ cells aggregation and differentiation to Col2.3-GFP ⁺ cells. Conclusion Mg ²⁺ promoted osseointegration around implants by facilitating the LepR ⁺ cells accumulation and osteogenic differentiation.