title: Preparation of germanium apatite and its cytotoxicity.
abstract: Germanium apatite was synthesized via the solid-state reaction between GeO(2) and (NH(4))(3)PO(4). The synthesized materials were characterized using XRD, and thermal analysis was carried out using TG-DTA. Ge(2)P(2)O(7) was preferentially produced at temperatures between 300-900 degrees C, and at temperatures above 1000 degrees C, germanium apatite (Ge(5)O(PO(4))(6), GeAp) was synthesized. In solubility tests, 0.36% and 0.65% of Ge ions were liberated from GeAp powder in distilled water at 37 and 80 degrees C after four weeks, respectively. A GeAp aqueous solution maintained at 37 degrees C was strongly acidic with a pH=1.67 after four weeks. The growth rate of human adult gingival fibroblast cells in a medium that included GeAp, HA, and GeO(2) was investigated. The growth rate of the cells in a 0.1 mg/ml GeAp medium was almost the same as that in the control. The cell growth was restricted in a 1.0 mg/ml GeAp medium, whereas the cell growth in a pH-adjusted 1.0 mg/ml GeAp medium at pH=7.60 was higher than that in non-adjusted medium at pH = 7.06.
authors.affiliation: Frontier Research and Development Center, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394, Japan. ozeki@frontier.dendai.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Ozeki
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
authors.forename: H
authors.initials: H
authors.lastname: Aoki
mesh_terms: D001031:Apatites / Q000737:chemistry / Q000633:toxicity*; D001672:Biocompatible Materials / Q000737:chemistry / Q000633:toxicity*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects*; D005857:Germanium / Q000737:chemistry / Q000633:toxicity*; D005881:Gingiva / Q000166:cytology* / Q000187:drug effects*; D006801:Humans; D008422:Materials Testing
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D005857:Germanium