It is a new hot pot in tissue engineering and regenerative medicine to study the effects of physicochemical properties of implanted biomaterials on regulating macrophage polarization to promote bone regeneration. In this study, we designed and fabricated mineralized collagen (MC) with different microporous structures via in vitro biomimetic mineralization method. The microporous structures, mechanical properties, shore hardness and water contact angle measurements were tested. Live/dead cell staining, CCK-8 assay, phalloidine staining, staining of focal adhesions were used to detect cell behavior. ELISA, qRT-PCR, ALP, and alizarin red staining (ARS) were performed to appraise osteogenic differentiation and investigated macrophage response and their subsequent effects on the osteogenic differentiation. The results showed that RAW264.7 and MC3T3-E1 cells were able to survive on the MC. MC with the microporous structure of approximately 84 μm and 70%–80% porosity could promote M2 macrophage polarization and increase the expression level of TGF-β and VEGF. Moreover, the gene expression of the osteogenic markers ALP, COL-1, and OCN increased. Therefore, MC with different microporous structures mediated osteoimmunomodulation in bone regeneration. These data will provide a new idea of biomaterials inducing bone repair and direct the optimal design of novel immune biomaterials, development, and rational usage.

研究植入生物材料的理化性质对调节巨噬细胞极化促进骨再生的影响，是组织工程和再生医学领域的新热点。在这项研究中，我们设计并制造了具有不同微孔结构的矿化胶原蛋白（MC）。体外仿生矿化法。测试了微孔结构、机械性能、肖氏硬度和水接触角测量值。活/死细胞染色、CCK-8测定、鬼笔环肽染色、粘着斑染色用于检测细胞行为。进行 ELISA、qRT-PCR、ALP 和茜素红染色 (ARS) 以评估成骨分化并研究巨噬细胞反应及其对成骨分化的后续影响。结果表明RAW264.7和MC3T3-E1细胞能够在MC上存活。微孔结构约为 84 μm 和 70%~80% 孔隙率的 MC 可促进 M2 巨噬细胞极化并增加 TGF-β 和 VEGF 的表达水平。此外，成骨标志物 ALP、COL-1 和 OCN 的基因表达增加。所以，具有不同微孔结构的MC介导骨再生中的骨免疫调节。这些数据将为诱导骨修复的生物材料提供新思路，指导新型免疫生物材料的优化设计、开发和合理使用。