Robotic in situ 3D bio-printing technology for repairing large segmental bone defects.

Introduction: The traditional clinical treatment of long segmental bone defects usually requires multiple operations and depends on donor availability. The 3D bio-printing technology constitutes a great potential therapeutic tool for such an injury. However, in situ 3D bio-printing remains a major challenge. Objectives: In this study, we report the repair of long segmental bone defects by in situ 3D bio-printing using a robotic manipulator 3D printer in a swine model. Methods: We systematically optimized bio-ink gelation under physiological conditions to achieve desirable mechanical properties suitable for bone regeneration, and a D-H kinematic model was used to improve printing accuracy to 0.5 mm. Results: These technical improvements allowed the repair of long segmental defects generated on the right tibia of pigs using 3D bio-printing within 12 min. The 3D bio-printing group showed improved treatment effects after 3 months. Conclusion: These findings indicated that robotic in situ 3D bio-printing is promising for direct clinical application.