Decoding the mechanical characteristics of the human anterior cruciate ligament entheses through graduated mineralization interfaces

作者：Jinghua Fang, Xiaozhao Wang, Huinan Lai, Wenyue Li, Xudong Yao, Zongyou Pan, Renwei Mao, Yiyang Yan, Chang Xie, Junxin Lin, Wei Sun, Rui Li, J. Wang, Jiacheng Dai, Kaiwang Xu, Xinning Yu, Tengjing Xu, Wangping Duan, Jin Qian, Hongwei Ouyang, Xuesong Dai · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-53542-5 · 被引用次数：17 · 研究领域：Bone Tissue Engineering Materials、Tribology and Wear Analysis、Diamond and Carbon-based Materials Research

The anterior cruciate ligament is anchored to the femur and tibia via specialized interfaces known as entheses. These play a critical role in ligament homeostasis and joint stability by transferring forces, varying in magnitude and direction between structurally and functionally dissimilar tissues. However, the precise structural and mechanical characteristics underlying the femoral and tibial entheses and their intricate interplay remain elusive. In this study, two thin-graduated mineralization regions in the femoral enthesis (~21 μm) and tibial enthesis (~14 μm) are identified, both exhibiting distinct biomolecular compositions and mineral assembly patterns. Notably, the femoral enthesis interface exhibits progressively maturing hydroxyapatites, whereas the mineral at the tibial enthesis interface region transitions from amorphous calcium phosphate to hydroxyapatites with increasing crystallinity. Proteomics results reveal that Matrix Gla protein uniquely enriched at the tibial enthesis interface, may stabilize amorphous calcium phosphate, while C-type lectin domain containing 11 A, enriched at the femoral enthesis interface, could facilitate the interface mineralization. Moreover, the finite element analysis indicates that the femoral enthesis model exhibited higher resistance to shearing, whereas the tibial enthesis model contributes to tensile resistance, suggesting that the discrepancy in biomolecular expression and the corresponding mineral assembly heterogeneities col...