Reconstruction of Rabbit Anterior Cruciate Ligament by Bone Marrow-Derived Mesenchymal Stem Cell Implantation Through a Weft-Knitted Silk Mesh Scaffold Covering a Whip-Shaped Core

Abstract

To investigate the feasibility of using whip core wrapped by silk weft knitted mesh sheath as a scaffold and bone marrow-derived mesenchymal stem cells (BMSCs) to reconstruct the rabbit anterior cruciate ligament (ACL), BMSC implantation using the mesh-whip scaffold was performed to construct a BMSC-scaffold complex. Then, the BMSC-scaffold complex was implanted into an animal model of an ACL deficient rabbit. Regenerated ACLs were then taken from the animal model three and six months after implantation, followed by hematoxylin-eosin and Masson staining, quantitative RT-PCR detection, as well as mechanical performance evaluation. The results showed that many Sharpey’s fibers had arranged regularly between the neo-ACL and the bone three months after surgery, and an interface structure formed six months after surgery. Regenerated ligaments contained silk fibers and suficient collagen. Type I collagen, type III collagen, and tenascin-C were all highly expressed in the experimental group compared to the control group (no BMSC implantation) in the regenerated ligaments. In addition, the maximum pullout force values of neo-ACL in the three- and six-month experimental groups were 70.6±17.8 N and 122.8±25.7 N, respectively. The findings suggest that BMSC implantation using the mesh-whip scaffold is a promising method to reconstruct rabbit ACL.