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Biomolecules and Tissue Properties
Published in Joseph W. Freeman, Debabrata Banerjee, Building Tissues, 2018
Joseph W. Freeman, Debabrata Banerjee
Octacalcium phosphate, Ca8H2(PO4)65H2O, has a layered structure involving apatitic and hydrated layers. Apatitic layers have calcium and phosphate distributed in a manner similar to that for HAP. Hydrated layers contain lattice water and less densely packed calcium and phosphate ions. Hydrated layer may form an interphase between HAP and the surrounding solution. These apatites have lower surface tensions and free energy barriers for nucleation, which means less energy is required to form them compared to HAP. They are less complex and could serve as crystalline intermediates to HAP.
Octacalcium phosphate with incorporated carboxylate ions: a review
Published in Science and Technology of Advanced Materials, 2022
Taishi Yokoi, Masaya Shimabukuro, Masakazu Kawashita
Biomaterials science is an important and large research field due to the diversity of these materials. Biomaterials include polymers, metals, ceramics, and composites of these materials [1], and biomaterials science is a discipline that brings together the wisdom of materials science. For example, modern ceramic biomaterials originated with the development of bioactive glass, i.e. glass with bone-bonding properties, by Hench [2]. There was a time when bioactive glass research was active in Japan; however, such research, including glass-ceramic research, is now in decline. Bioactive inorganic/organic hybrid research [3,4] also ended following a temporary boom. On the other hand, research on calcium phosphate-based biomaterials, which began a little later than that on bioactive glass, remains one of the most important fields of ceramic biomaterials research [5], and calcium phosphate compounds have become indispensable in the study of biomaterials, especially ceramic-based biomaterials. Among calcium phosphate compounds, octacalcium phosphate (OCP) has unique properties in that it can incorporate carboxylate ions into its layered crystal structure. Only OCP exhibits such specific crystallographic properties, and we consider that these properties could lead to the development of various materials, including biomaterials. In this review, we will focus on calcium phosphate, particularly OCP with incorporated carboxylate ions, which is expected to be a next-generation material that will allow the flexible design of various functionalities.
Phosphate removal from food industry wastewater by chemical precipitation treatment with biocalcium eggshell
Published in Journal of Environmental Science and Health, Part A, 2021
Cristina Morales-Figueroa, Alejandra Teutli-Sequeira, Ivonne Linares-Hernández, Verónica Martínez-Miranda, Laura Garduño-Pineda, Carlos E. Barrera‐Díaz, Marco A. García-Morales, Miroslava A. Mier-Quiroga
According to Ferro-Guedes,[22] Ca/P ratios in sludge and solubilities are important parameters to distinguish between crystalline and amorphous forms. In general, when the Ca/P ratio is low, the calcium phosphate phase is more acidic and soluble. For a Ca/P molar ratio of approximately 1.18–2.50, a high pH (10–12) is necessary for the formation of an amorphous calcium phosphate. In this case, the stoichiometric ratio (Ca/P) used was 1.25, indicating the possible precipitation of octacalcium phosphate (OCP), amorphous calcium phosphate (ACP) and hydroxyapatite (PAH). The study of Wang and Nancolla[57] shows the chemical composition of calcium orthophosphates and their relationship with the concentrations of the Ca/P molar ratio.