Promotion of bone-tendon healing after ACL reconstruction using scaffold-free constructs comprising ADSCs produced by a bio-3D printer in rabbit models

Abstract

Background/Objective: This study evaluated the impact of adipose tissue-derived mesenchymal stromal cells (ADSCs) on bone-tendon healing in rabbit anterior cruciate ligament (ACL) reconstruction.

Methods

Nineteen mature male Japanese White rabbits underwent bilateral ACL reconstruction. ADSC constructs were implanted in the right femoral bone tunnel of each rabbit (implant group), while the left knee served as the control group without implantation. Nine rabbits were sacrificed at 3 and 6 weeks post-surgery, while the remaining were sacrificed immediately post-surgery. Biomechanical and micro computed tomography evaluations were conducted on six rabbits, while histological observation was performed on the remaining three.

Results

showed: (1) The implant group exhibited a significantly greater failure load than the control group at 3 weeks post-surgery. (2) Initially, the amount of new bone in the femoral tunnel was lower in the implant group at 3 weeks but surpassed that of the control group by 6 weeks. (3) Histological analysis indicated faster bone-tendon healing in the implant group than that of the control.

Conclusion

These findings suggest a positive effect of ADSC constructs on bone-tendon healing post-ACL reconstruction in rabbits. However, further studies using larger animal models must confirm these effects comprehensively.

The translational potential of this article

The method of transplanting a scaffold-free autologous ADSC construct is a technique that can safely and reliably transplant ADSCs to the tendon-bone tunnel interface without using foreign substances. It can be applied to bone-tendon healing in ACL reconstruction surgery and other areas, such as the rotator cuff and Achilles tendon attachment site.