Research Progress on Hierarchical Structure of Cortical Bone and Its Toughening Mechanisms / 医用生物力学

Cortical bone is a kind of natural biological composite materials, which is mainly composed of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals. It possesses high strength, stiffness and fracture toughness and has the ability to tolerate damage and self-heal. In the long process of evolution, bone tissues form the biomechanical strength and toughness to meet its functional needs. The excellent mechanical properties of cortical bone are closely related to its hierarchical microstructure. This paper reviewed the hierarchical microstructure of cortical bone and its toughening mechanisms, which would contribute to understanding the diagnosis, prevention and treatment of aging-related osteoporosis and the pathological mechanism of bone diseases.

Research progress of bone microarchitecture and microdamage detection / 中国组织工程研究

BACKGROUND:Bone fragility and poor bone quality due to osteoporosis are a major and increasing concern. Bone microarchitecture and microdamage, the important factors of bone quality, their detection technology and instrument have experienced a long development process. OBJECTIVE:To give a brief introduction of the concept of the bone microarchitecture and microdamage, then to summarize the research progress of their detective methods. METHODS:PubMed and CNKI databases were retrieved for reviews and articles related to bone microarchitecture and microdamage published from January 1990 to June 2016 using the keywords of“bone microarchitecture, bone microdamage and detect/detective/detecting”in Chinese and English, respectively. Finaly a total of 65 articles were selected for overview. RESULTS AND CONCLUISON:(1) Bulk staining is a quick and useful way to confirm and assess linear microcracks and diffuse damage. Micro-CT and confocal microscopy al ow visualization at the micron scale, and are useful tools to understand the three-dimentional nature of bone microdamage. Scanning electron microscope lacks the ability to investigate large regions of microdamage, but al ows users to probe in extensive details at the nano scale. (2) Ultimately, we recommend the use of multiple imaging modalities according to the experimental needs to obtain useful information about bone quality and microdamage formation, across the scales of hierarchy in bone.