Fig. 2

Crosstalk between Mϕs and BMSCs in bone healing. a Bones are able to produce Mϕs to regulate the inflammatory response. b–d Mϕs are classified into three subtypes. e M₀Mϕs have a strong ability to promote the osteogenesis of BMSCs. f M₁Mϕs participate in the inflammation response under the regulation of BMSCs in the early stage of bone injury. g M₂Mϕs are preferred to induce BMSCs to form thick cell sheets and BMSCs are able to enhance the osteogenic promotion of M₂Mϕs. h–k BMSCs have the ability to differentiate into various tissue cells. l BMSCs are the main functional cells in the process of bone healing