Abstract
The conversion of glass to a hydroxyapatite (HA) material in an aqueous phosphate solution is used as an indication of the bioactive potential of the glass, as well as a low temperature route for preparing biologically useful materials. In this work, the effect of varying concentrations of pyrophosphate ions in the phosphate solution on the conversion of a calcium–lithium–borate glass to HA was investigated. Particles of the glass (150–355 μm) were immersed for up to 28 days in 0.25 M K2HPO4 solution containing 0–0.1 M K4P2O7. The kinetics of degradation of the glass particles and their conversion to HA were monitored by measuring the weight loss of the particles and the ionic concentration of the solution. The structure and composition of the conversion products were analyzed using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. For K4P2O7 concentrations of up to 0.01 M, the glass particles converted to HA, but the time for complete conversion increased from 2 days (no K4P2O7) to 10 days (0.01 M K4P2O7). When the K4P2O7 concentration was increased to 0.1 M, the product consisted of an amorphous calcium phosphate material, which eventually crystallized to a pyrophosphate product (predominantly K2CaP2O7 and Ca2P2O7). The consequences of the results for the formation of HA materials and devices by the glass conversion route are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Hench LL. Bioceramics. J Am Ceram Soc. 1998;81:1705–28
Rahaman MN, Brown RF, Bal BS, Day DE. Bioactive glasses for nonbearing applications in total joint replacement. Semin Arthroplasty. 2006;17:102–12.
Jones JR, Gentleman E, Polak J. Bioactive glass scaffolds for bone regeneration. Elements. 2007;3:393–9.
Hench LL, Splinter RJ, Allen WC, Greenlee TK Jr. Bonding mechanisms at the interface of ceramic prosthetic materials. J Biomed Mater Res. 1971;5:117–41.
Pantano CG, Clark AE, Hench LL. Multilayer corrosion films on Bioglass surfaces. J Am Ceram Soc. 1974;57:412–3.
Hench LL, Wilson J. Surface-active biomaterials. Science. 1984;226:630–6.
Ducheyne P, Qiu Q. Bioactive ceramics: the effect of surface reactivity on bone formation and bone cell function. Biomaterials. 1999;20:2287–303.
Day DE, White JE, Brown RF, McMenamin KD. Transformation of borate glasses into biologically useful materials. Glass Technol. 2003;44:75–81.
Wang Q, Huang W, Wang D, Darvell BW, Day DE, Rahaman MN. Preparation of hollow hydroxyapatite microspheres. J Mater Sci: Mater Med. 2006;17:641–6.
Conzone SD, Day DE. Preparation and properties of porous microspheres made from borate glass. J Biomed Mater Res A. 2009;88A:531–42.
Fu H, Rahaman MN, Day DE. Effect of process variables on the microstructure of hollow hydroxyapatite microspheres prepared by a glass conversion process. J Am Ceram Soc. 2010. doi:10.1111/j.1551-2916.2010.03833.x.
Han X, Du M, Ma Y, Day DE. Evaluation of hydroxyapatite microspheres made from a borate glass to separate protein mixtures. J Mater Sci. 2008;43:5618–25.
Huang W, Day DE, Kittiratanapiboon K, Rahaman MN. Kinetics and mechanisms of the conversion of silicate (45S5), borate, and borosilicate glasses to hydroxyapatite in dilute phosphate solutions. J Mater Sci: Mater Med. 2006;17:583–96.
Huang W, Rahaman MN, Day DE, Li Y. Mechanisms of converting silicate. borate, and borosilicate glasses to hydroxyapatite in dilute phosphate solutions. Phys Chem Glasses: Eur J Glass Sci Technol B. 2006;47:647–58.
Huang W, Day DE, Rahaman MN. Comparison of the formation of calcium and barium phosphates by the conversion of borate glass in dilute phosphate solution at near room temperature. J Am Ceram Soc. 2007;90:838–44.
Yao A, Wang D, Huang W, Fu Q, Rahaman MN, Day DE. In vitro bioactive characteristics of borate-based glasses with controllable degradation behavior. J Am Ceram Soc. 2007;90:303–6.
Fu Q, Rahaman MN, Day DE. Accelerated conversion of silicate bioactive glass (13–93) to hydroxyapatite in aqueous phosphate solution containing polyanions. J Am Ceram Soc. 2009;92:2870–6.
Clark AE, Hench LL. Early stages of calcium-phosphate layer formation in bioglass. J Non-Cryst Solids. 1989;113:195–202.
Filgueiras MR, LaTorre G, Hench LL. Solution effects on the surface reaction of a bioactive glass. J Biomed Mater Res. 1993;27:445–53.
Rehman I, Bonfield W. Characterization of hydroxyapatite and carbonated apatite by photo acoustic FTIR spectroscopy. J Mater Sci: Mater Med. 1997;8:1–4.
Harcharras M, Ennaciri A, Assaaoudi H. Vibrational spectra of double diphosphates M2SrP2O7 (M = Li, Na, K, Rb, Cs). J Can Anal Sci Spectrosc. 2001;46:83–8.
Harcharras M, Ennaciri A, Rulmont A, Gilbert B. Vibrational spectra and structures of double diphosphates M2CdP2O7 (M = Li, Na, K, Rb, Cs). Spectrochim Acta. 1997;A53:345–52.
Sarr O, Diop L. The vibrational spectra of the crystalline tripotassium hydrogen pyrophosphates K3HP2O7·3H2O and K3HP2O7. Spectrochim Acta. 1984;A40:1011–5.
Li Y, Rahaman MN, Bal BS, Day DE, Fu Q. Early stages of calcium phosphate formation on bioactive borosilicate glass in aqueous phosphate solution. J Am Ceram Soc. 2008;91:1528–33.
Christoffersen J, Christoffersen MR. Kinetics of dissolution of calcium hydroxyapatite: IV. The effect of some biologically important inhibitors. J. Crys Growth. 1981;53:42–54.
Christoffersen MR, Balic-Zunic T, Pehrson S, Christoffersen J. Kinetics of growth of triclinic calcium pyrophosphate dehydrate crystals. Cryst Growth Des. 2001;1:463–6.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Fu, H., Rahaman, M.N., Day, D.E. et al. Effect of pyrophosphate ions on the conversion of calcium–lithium–borate glass to hydroxyapatite in aqueous phosphate solution. J Mater Sci: Mater Med 21, 2733–2741 (2010). https://doi.org/10.1007/s10856-010-4130-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10856-010-4130-5