(a) Schematic of experimental design. Four groups were evaluated including 2D tissue culture plastic (TCP), uncoated μRB scaffolds, and μRB scaffolds coated with nMSCM or pMSCM. (b, c) Normalized gene expressions of M1 Mφ markers (b) and M2 Mφ markers (c) at 8 hours after seeding; (d, e) ELISA measurement of TNF-α (d) and IL-10 (e) released by Mφ after seeding on TCP or different μRB scaffolds for 24 hours. (f) Evaluating the effects of Mφ condition medium and MSCM coating on MSC osteogenesis in vitro. (g) Alizarin red S staining showed conditioned medium (CM) from Mφ in TCP and μRB alone inhibited MSC mineralization, whereas MSCM coating rescued MSC mineralization. Scale bar: 200 μm. Data are represented as mean ± S.D. (n = 4/group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.