title: Unraveling the role of Calcium ions in the mechanical properties of individual collagen fibrils.
abstract: Collagen, the dominating material in the extracellular matrix, provides the strength, elasticity and mechanical stability to the organisms. The mechanical property of collagen is mainly dominated by its surrounding environments. However, the variation and origin of the mechanics of collagen fibril under different concentrations of calcium ions (χCa) remains unknown. By using the atomic force microscopy based nanoindentation, the mechanics and structure of individual type II collagen fibril were first investigated under different χCain this study. The results demonstrate that both of the mechanical and structural properties of the collagen fibril show a prominent dependence on χCa. The mechanism of χCa-dependence of the collagen fibril was attributed to the chelation between collagen molecules and the calcium ions. Given the role of calcium in the pathology of osteoarthritis, the current study may cast new light on the understanding of osteoarthritis and other soft tissue hardening related diseases in the future.
authors.affiliation: Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, P. R. China.|Department of Physics and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Xiangchao
authors.initials: X
authors.lastname: Pang
authors.affiliation: Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou 510515, P. R. China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, P. R. China.|ShenZhen Key Lab of Nanoimprint, Shenzhen, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Tang
mesh_terms: D001696:Biomechanical Phenomena; D002118:Calcium / Q000378:metabolism*; D024043:Collagen Type II / Q000737:chemistry*; D055119:Elastic Modulus; D024022:Fibrillar Collagens / Q000737:chemistry*; D006801:Humans; D007477:Ions; D008875:Middle Aged
chemical_list: D024043:Collagen Type II; D024022:Fibrillar Collagens; D007477:Ions; D002118:Calcium