title: Preparation and characterization of novel alkali-activated nano silica cements for biomedical application.
abstract: The major goal of this study was to investigate and characterize novel Ca(OH)(2)-activated nano silica (SiO(2)) cements for the potential application as a bone cement. Novel Ca(OH)(2)-activated nano-SiO(2) powders composed of Ca(OH)(2) and nano-SiO(2) were easily prepared, and the deionized water was used as the liquid phase. The initial and final setting times of Ca(OH)(2)-activated nano-SiO(2) cements with liquid to powder (L/P) ratios of 1.00-1.33 mL g(-1) range from 50 ± 1 to 120 ± 3 min and 96 ± 2 to 190 ± 5 min, respectively. The calorimetric curves indicate that the heat liberations of Ca(OH)(2)-activated nano-SiO(2) cements (105.57-138.01 J g(-1)) are lower than that of C(3)S (about 150 J g(-1)). The Ca(OH)(2)-activated nano-SiO(2) pastes are injectable under general extrusion force of 100 N, and their compressive strengths with suitable L/P ratios are 5-9 MPa, which is comparable with that of cancellous bone. The in vitro bioactivity of the Ca(OH)(2)-activated nano-SiO(2) cement pastes were investigated by soaking in simulated body fluid for various periods. The results show amorphous apatite deposits on the paste surfaces after soaking in simulated body fluid for 2 h. With the prolonged soaking time, amorphous apatite transforms into crystalline apatite after soaking for 1 day. The Ca(OH)(2)-activated nano-SiO(2) cements have short setting times, low heat liberation, injectability, suitable compressive strength, and excellent in vitro bioactivity, and may be used as bioactive bone cements for bone regeneration.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lin
authors.forename: Xianghui
authors.initials: X
authors.lastname: Lan
authors.forename: Yanbao
authors.initials: Y
authors.lastname: Li
authors.forename: Yaru
authors.initials: Y
authors.lastname: Ni
authors.forename: Chunhua
authors.initials: C
authors.lastname: Lu
authors.forename: Yixin
authors.initials: Y
authors.lastname: Chen
authors.forename: Zhongzi
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D001672:Biocompatible Materials; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D012822:Silicon Dioxide
chemical_list: D000468:Alkalies; D001672:Biocompatible Materials; D012822:Silicon Dioxide