Application of 3D-printed bredigite scaffolds in Onlay graft in rats

To evaluate the osteogenic effects of using a 3D-printed bredigite(BRT) bone scaffold on the Onlay graft in rats.

BRT scaffold material was fabricated by 3D printing technology as the experimental group, β-tricalcium phosphate(β-TCP) bone scaffolds were used as the control group. The scaffolds were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical test and in vitro degradation test. An animal model of Onlay graft in SD rats was established. According to the different grafts, the animal model was divided into autogenous bone transplantation group (Auto Group), β- TCP group and BRT group. At 12 weeks after the operation, the target line was obtained for gross observation, micro CT scanning and analysis, and HE staining histological analysis.

BRT scaffolds have distinctive surface topographywith relatively uniformly sized pores in SEM imaging. A higher mechanical strength and degradation rate was obtained with BRT scaffolds (46.80 ± 3.44) MPa, compared to β- TCP scaffolds (11.29 ± 1.30) MPa (P< 0.001). At day 35 in vitro, the mass of BRT was degraded 27.18% ± 1.41%, and the Ca, Mg and Si ion concentrations were maintained at a high level in BRT group. Micro CT and histological quantitative results showed that the proportion of bone regeneration in BRT group was 16.83% ± 2.11% and 19.08% ± 2.17%, respectively, which was higher than that in the β- TCP group (8.48% ± 1.85%, 10.81% ± 1.33%) (P < 0.05).

3D-printed BRT scaffolds promote bone regeneration in the Onlay graft.