Preparation of Decellularized Triphasic Hierarchical Bone‐Fibrocartilage‐Tendon Composite Extracellular Matrix for Enthesis Regeneration

Abstract Tendon to bone (enthesis) rupture, which may cause disability and persistent pain, shows high rate of re‐rupture after surgical repair. Tendon or enthesis scaffolds have been widely studied, but few of these materials can recapitulate the tissue continuity. Thus, this study is conducted to prepare a triphasic decellularized bone‐fibrocartilage‐tendon (D‐BFT) composite scaffold. The D‐BFT scaffold is developed using a combination of physical, chemical, and enzymatic treatments using liquid nitrogen, Triton‐X 100, sodium‐dodecyl sulfate, and DNase I, which effectively removes the cell components while preserving the biological composite and microstructure. Moreover, the mechanical properties of D‐BFT are highly preserved and similar to those of the human Achilles tendon. Additionally, in vitro, mesenchymal stem cells (MSCs) adhered, proliferated, and infiltrated into the D‐BFT scaffold, and MSC differentiation is confirmed by up‐regulation of osteogenic‐related and tenogenic‐related genes. The repair outcomes are explored by applying the D‐BFT scaffold in the model of femur‐tibia defects in vivo, which shows good repair results. Thus, the D‐BFT scaffold developed in this study is a promising graft for enthesis regeneration.