title: The use of physiological solutions or media in calcium phosphate synthesis and processing.
abstract: This review examined the literature to spot uses, if any, of physiological solutions/media for the in situ synthesis of calcium phosphates (CaP) under processing conditions (i.e. temperature, pH, concentration of inorganic ions present in media) mimicking those prevalent in the human hard tissue environments. There happens to be a variety of aqueous solutions or media developed for different purposes; sometimes they have been named as physiological saline, isotonic solution, cell culture solution, metastable CaP solution, supersaturated calcification solution, simulated body fluid or even dialysate solution (for dialysis patients). Most of the time such solutions were not used as the aqueous medium to perform the biomimetic synthesis of calcium phosphates, and their use was usually limited to the in vitro testing of synthetic biomaterials. This review illustrates that only a limited number of research studies used physiological solutions or media such as Earle's balanced salt solution, Bachra et al. solutions or Tris-buffered simulated body fluid solution containing 27mM HCO3(-) for synthesizing CaP, and these studies have consistently reported the formation of X-ray-amorphous CaP nanopowders instead of Ap-CaP or stoichiometric hydroxyapatite (HA, Ca10(PO4)6(OH)2) at 37°C and pH 7.4. By relying on the published articles, this review highlights the significance of the use of aqueous solutions containing 0.8-1.5 mMMg(2+), 22-27mM HCO3(-), 142-145mM Na(+), 5-5.8mM K(+), 103-133mM Cl(-), 1.8-3.75mM Ca(2+), and 0.8-1.67mM HPO4(2-), which essentially mimic the composition and the overall ionic strength of the human extracellular fluid (ECF), in forming the nanospheres of X-ray-amorphous CaP.
authors.affiliation: Department of Materials Science and Engineering, University of Illinois, Urbana, IL 61801, USA. Electronic address: c_tas@hotmail.com.
authors.forename: A Cuneyt
authors.initials: AC
authors.lastname: Tas
mesh_terms: D032701:Biomimetics; D001826:Body Fluids / Q000378:metabolism*; D002130:Calcium Phosphates / Q000138:chemical synthesis*; D003094:Collagen / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D012996:Solutions
chemical_list: D002130:Calcium Phosphates; D003470:Culture Media; D012996:Solutions; D003094:Collagen; C020243:calcium phosphate
keywords: Biomimetic; Calcium phosphate; Physiological media; Synthesis