School of Biology & Engineering, Guizhou Medical University, Guiyang 550025, China
School of Medicine, South China University of Technology, Guangzhou 510006, China
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
Key Laboratory of Biomedical Engineering of Guangdong Province, South China University of Technology, Guangzhou 510006, China
Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, China
Innovation Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
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Graphical Abstract
The nanoscale plastic deformation process in bone includes the first stage (slipping between fibril arrays) characterized by mineral aggregate grains, and the second stage (interfibrillar slipping) with the feature of the exposed mineralized collagen fibrils.
Abstract
The structural origins of bone toughness at the nanoscale are not completely understood. Therefore, we performed insitu scanning using atomic force microscopy during macroscopic mechanical testing of antler and bovine bone, to reveal the origins of the irreversible plastic deformation at the mineralized collagen fibril (MCF) array and MCF levels. We found that the plastic deformation behavior at the nanoscale level could be divided into two stages. The first stage of plastic deformation at the nanoscale level was characterized by slippage between the MCF arrays, which contained mineral aggregate grains with regular shapes under load. In the second stage of nanoscale plastic deformation, the MCFs broke through the bonds of the extrafibrillar mineral aggregate grains and exhibited interfibrillar slippage. These nanoscale plastic deformation behaviors may thus be the origins of stress whitening and irreversible plastic deformation. Thus, the findings in this study not only shed light on the plastic deformation mechanisms of MCF arrays and MCFs, but also provide structural and mechanistic insights into bioinspired materials design and mechanisms of relevant bone diseases.
Qian T, Teng L, Zhou Y, et al. Nanostructural origins of irreversible deformation in bone revealed by an insitu atomic force microscopy study. Nano Research, 2022, 15(8): 7329-7341. https://doi.org/10.1007/s12274-022-4365-8