Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Growth of fibrous hydroxyapatite in the gel system

  • 115 Accesses

  • 56 Citations


Hydroxyapatite (HAP) was prepared in the agar gel system, where Ca2+ ions were incorporated in the gel and PO 4 3− solution was layered over the gel. When the concentration of Ca2+ was lower than 1.0 M and the initial solution Ca/P molar ratio was lower than about unity, fibrous HAP several centimetres to several tens of centimetres in length was grown upwards in the PO 4 3− solution from the gel phase, while at the larger Ca2+ concentration and initial Ca/P molar ratio CaHPO4 · 2H2O (DCPD) in the form of gelatinous precipitate, particulate precipitates or needle-like crystals were preferred to HAP. The fibrous HAP was calcium deficient and composed of small elongated hollow ovals linked in a zigzag row. This was considered to be formed in the following manner. First, Ca2+ ions supplied through pores in the gel reacted with PO 4 3− ions to form a small spherulite at the pore exit, then the spherulite was bloated and elongated by the osmotic pressure or capillary force until a part of the oval was broken for Ca2+ ions to be gushed out into the PO 4 3− solution. The above two processes were repeated to form elongated hollow ovals linked to the preceding ones.

This is a preview of subscription content, log in to check access.


  1. 1.

    A. Makishima andH. Aoki, in “Bioceramics” (in Japanese), edited by T. Yamaguchi and H. Yanagida (Gihodo, Tokyo, 1984).

  2. 2.

    K. Kanazawa, T. Umegaki andH. Monma,Seramikkusu (Ceramics) 10 (1975) 461.

  3. 3.

    M. Jarcho, C. H. Bolen, M. B. Thomas, J. Bobick, J. F. Kay andR. H. Doremus,J. Mater. Sci. 11 (1976) 2027.

  4. 4.

    H. K. Henisch, “Crystal growth in gels” (Pennsylvania State University Press, University Park and London, 1970).

  5. 5.

    G. K. Hunter, B. L. Allen, M. D. Grynpas andP.-T. Cheng,Biochem. J. 228 (1985) 463.

  6. 6.

    R. Z. LeGeros, D. Lee, G. Quirolgico, W. P. Shirra andL. Reiche,Scanning Electron Microscopy (1983) 407.

  7. 7.

    T. Umegaki, S. Shiba andT. Kanazawa,Yogyo-Kyokai-Shi 92 (1984) 612.

  8. 8.

    H. Monma, S. Ueno andT. Kanazawa,J. Chem. Tech. Biotechnol. 31 (1981) 15.

  9. 9.

    J. A. S. Bett, L. G. Cristner andW. K. Hall,J. Amer. Chem. Soc. 89 (1967) 5535.

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kamiya, K., Yoko, T., Tanaka, K. et al. Growth of fibrous hydroxyapatite in the gel system. J Mater Sci 24, 827–832 (1989). https://doi.org/10.1007/BF01148764

Download citation


  • Polymer
  • 2H2O
  • Agar
  • Hydroxyapatite
  • Initial Solution