Fig. 1. Overview of the experimental design and methodologies.

Fig. 2. SEM images, elemental composition, and pore size distribution of pTi and SiC-pTa scaffolds. (a-c) SEM images of pTi scaffolds at low, medium, and high magnifications, showing their lamellar pore architecture with visible particles. (d-f) Morphology of SiC-pTa scaffolds at different magnifications, revealing a highly interconnected, trabecular bone-like pore structure with a rough, densely packed crystalline surface. (g-j) EDS spectra of pTi and SiC-pTa scaffolds, indicating that pTi is mainly composed of Ti, Al, and V, whereas SiC-pTa primarily contains tantalum with high purity. (k) Pore size distribution curves, showing larger and more narrowly distributed pores in SiC-pTa scaffolds, while pTi scaffolds exhibited smaller pores with a comparable distribution range (n  = 3).

Fig. 3. Morphological observation and proliferation analysis of MC3T3-E1 cells on pTi and SiC-pTa scaffolds. (a-c) SEM images of pTi scaffolds on days 1, 3, and 7, showing relatively few cells with limited spreading. (d-f) SEM images of SiC-pTa scaffolds at the same time points, demonstrating good cell attachment, progressive spreading, and multilayer formation. (g-l) Calcein-AM/PI double-staining images showing a gradual increase in the number of green viable cells in the SiC-pTa group on days 1, 3, and 7, with higher cell density and greater spreading than the pTi group, suggesting that SiC-pTa scaffolds provide a more favorable environment for cell adhesion and proliferation (**P < 0.01, ***P < 0.001, n = 5).

Fig. 4. CCK-8 assay results showing significantly higher OD values in the SiC-pTa group compared with the pTi group on days 5 and 7, indicating enhanced cell viability and proliferation (**P  < 0.01, ***P < 0.001, n = 6).

Fig. 5. Effects of pTi and SiC-pTa scaffolds on the expression of osteogenic markers. (a-d) RT-qPCR analysis of osteogenesis-related gene expression, showing that ALP, OCN, OPN, and Runx2 were significantly upregulated in the SiC-pTa group compared with the pTi and NC groups on days 7 and 14. (e, g) Western blot detection of osteogenic proteins ALP, Runx2, and OPN in MC3T3-E1 cells on day 7 (e) and day 14 (g), with β-Actin as the internal control. (f, h) Corresponding densitometric analysis of protein bands, indicating significantly higher expression levels of ALP, Runx2, and OPN in the SiC-pTa group compared with the pTi and NC groups at both time points (*P < 0.05, **P < 0.01, ***P < 0.001, n = 3).

Fig. 6. Evaluation of bone formation and osseointegration of pTi and SiC-pTa implants in rabbit femora. (a) Micro-CT three-dimensional reconstruction images of the implant sites, where blue regions represent implanted screws and green regions indicate newly formed bone. At both time points, the SiC-pTa group exhibited markedly greater bone formation than the pTi group. (b) Quantitative analysis of BV/TV around the implants, showing significantly higher values in the SiC-pTa group compared with the pTi group (*P < 0.05, **P < 0.01, n = 5).

Fig. 7. Comparison of VG-stained histological sections of pTi and SiC-pTa implants at 1 and 3 months postoperatively. (a, b) New bone formation in the pTi group at 1 M and 3 M; (c, d) new bone formation in the SiC-pTa group at 1 M and 3 M. Black areas indicate scaffold pores, red areas represent newly formed bone, and yellow areas correspond to fibrous tissue. The SiC-pTa group consistently exhibited more extensive bone ingrowth and enhanced osseointegration at both time points.