Blood is the medium which provides the vital inorganic ions, biological molecules, growth factors, proteins, and vitamins to the nanocrystals formed by cells in human hard tissues, i.e., bones and teeth. Blood pH is stabilized at 7.4 by a fine balance between carbonic anhydrase and bicarbonate ions. For a healthy person, blood temperature is confined to 36.5°C. Inorganic ions (such as Ca~(2+), Mg~(2+), Na~+, K~+, HCO_3~-, HPO_4~(2-), Cl~-) present in blood are also found in the nanocrystals of hard tissues. These nanocrystals are not stoichiometric hydroxyapatite, but they are non-stoichiometric and heavily doped substances. Biomimetic syntheses performed at 36.5°C and pH 7.4 in synthetic biomineralization media, free of any synthetic, man-made organics, produce calcium phosphates of high BET surface area. This article focuses on summarizing our continuing efforts in developing new biomineralization media (BM-3, BM-7, Lac-SBF, Tris-SBF and urea-enzyme urease-buffered solutions) and the biomimetic synthesis of non-stoichiometric and doped calcium phosphate- and calcium carbonate-based hard tissue substitute materials. The specifics of media development and the full characterization (via electron microscopy, XRD, FTIR, ICP-AES, BET, and cell culture) of the synthesized biomaterials are summarized.
展开▼
