[Selective Laser Sintering-produced porous titanium alloy scaffold for bone tissue engineering].

OBJECTIVE: To evaluate the biocompatibility of SLS-produced titanium alloy scaffold in vitro and investigate the therapeutic effects in repairing segmental bone defects.

METHODS: Porous titanium alloy scaffolds were produced by SLS and their surfaces were either left untreated or acid etched. In vitro, mouse pre-osteoblasts (MC3T3-E1 cells) were cultured on these 2 group scaffolds, and then cell proliferation and differentiation were examined after cell seeding. In vivo, bone defects were artificially made in 15 New Zealand rabbits and the porous titanium specimens were implanted into the radius of rabbits for 3 months. The regulating checks of X-ray were determined. The osteointegration of the implants was investigated by Micro-CT and histological examination at 12 weeks after surgery.

RESULTS: A gradual increase in cell-specific ALP synthesis by cells cultured in both groups was observed with longer culture time (14 d). ALP activity did not differ significantly between two groups (0.834 ± 0.092 vs 0.815 ± 0.081, P > 0.05) . Both Micro-CT and the histological analysis indicated that the titanium alloy scaffolds had excellent ability to facilitate the osteointegration in vivo. The results were significantly different between the empty control and the 2 different surface modifications of SLS-implants (25.4% ± 4.2% vs 23.6% ± 8.4% vs 12.3% ± 4.7%, P < 0.05). Between the groups with implants, the number of bone points was not significantly different, irrespective of the surface treatment (25.4% ± 4.2% vs 23.6% ± 8.4%, P > 0.05).

CONCLUSION: Selective Laser Sintering-Produced porous titanium alloy scaffold possessed admirable biocompatibility in vitro. It also could be contributed to the healing of long tulular bone defect. The porous Ti6Al4V implant not only reduced the stress-shielding but also exerted appropriate osteoconductive properties.