title: The role of the collaborative functions of the composite structure of organic and inorganic constituents and their influence on the electrical properties of human bone.
abstract: BACKGROUND
  The electrical potential, which is generated in bone by collagen displacement, has been well documented. However, the role of mineral crystals in bone piezoelectricity has not yet been elucidated.
  
  
  OBJECTIVE
  We examined the mechanism that the composite structure of organic and inorganic constituents and their collaborative functions play an important role in the electrical properties of human bone.
  
  
  METHODS
  The electrical potential and bone structure were evaluated using thermally stimulated depolarized current (TSDC) and micro computed tomography, respectively. After electrical polarization of bone specimens, the stored electrical charge was calculated using TSDC measurements. The CO3/PO4 peak ratio was calculated using attenuated total reflection to compare the content of carbonate ion in the bone specimens.
  
  
  RESULTS
  The TSDC curve contained 3 peaks at 100, 300 and 500°C, which were classified into 4 patterns. The CO3/PO4 peak ratio positively correlated with the stored charges at approximately 300°C in the polarized bone. There was a positive correlation between the stored bone charge and the bone mineral density only.
  
  
  CONCLUSIONS
  It is suggested that the peak at 300°C is attributed to carbonate apatite and the total bone mass of human bone, not the three-dimensional structure, affects the stored charge.
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
authors: Kazuhiro
authors: K
authors: Kohata
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
authors: Soichiro
authors: S
authors: Itoh
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
authors: Naohiro
authors: N
authors: Horiuchi
authors: Department of Orthopedic Surgery, Kawakita General Hospital, 1-7-3 Asagaya-kita, Suginami-ku, Tokyo 166-8588, Japan.
authors: Taro
authors: T
authors: Yoshioka
authors: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
authors: Kimihiro
authors: K
authors: Yamashita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001031:Apatites / Q000032:analysis / Q000737:chemistry*; D015519:Bone Density; D004560:Electricity; D005260:Female; D005272:Femur Neck / Q000033:anatomy & histology / Q000737:chemistry*; D006801:Humans; D008297:Male
chemical_list: D001031:Apatites; C030782:carboapatite
keywords: Electrical property; bone mineral density; carbonate apatite; electrical polarization; human bone