Abstract: Ti₃SiC₂ ceramics exhibit excellent mechanical properties and good biocompatibility, rendering them promising bone substitutes for load-bearing conditions. However, the bone integration and osteogenic ability of Ti₃SiC₂ ceramics remain unclear. Herein, porous Ti₃SiC₂ ceramics were prepared and systematically investigated as bone scaffolds. The Ti₃SiC₂ scaffolds with a porosity of 62.9 % ± 2.5 % showed high compressive strength ∼68.12 ± 4.33 MPa. Silicon hydroxyl groups formed on the surface of Ti₃SiC₂ after soaking in simulated body fluid, which played a critical role in the apatite mineralization of the scaffolds. Biomineralization of Ti₃SiC₂ scaffolds was found when implanted subcutaneously in the rat dorsum for 2 weeks, demonstrating good osteogenesis ability. The apatite mineralization of the Ti₃SiC₂ scaffold facilitated the polarization of RAW264.7 cells from M1 to M2 phenotype, which also promoted the differentiation of MC3T3-E1 cells. The porous Ti₃SiC₂ scaffolds improved osteointegration and bone regeneration after implantation in rabbit femoral defects. Impressively, the number of the newly formed trabeculae in the Ti₃SiC₂ group was three times of the control group after implantation for 8 weeks, showing excellent bone defect repair. This work demonstrates that Ti₃SiC₂ implants with improved biological functions likely via in-situ biomineralization are promising candidates for bone regeneration.

Key words: Ti₃SiC₂ scaffolds, Biomineralization, Macrophage polarization, Bone regeneration