Zinc-substituted hydroxyapatite: a biomaterial with enhanced bioactivity and antibacterial properties

  • E. S. Thian
  • T. Konishi
  • Y. Kawanobe
  • P. N. Lim
  • C. Choong
  • B. Ho
  • M. Aizawa


Hydroxyapatite (HA) is a synthetic biomaterial and has been found to promote new bone formation when implanted in a bone defect site. However, its use is often limited due to its slow osteointegration rate and low antibacterial activity, particularly where HA has to be used for long term biomedical applications. This work will describe the synthesis and detailed characterization of zinc-substituted HA (ZnHA) as an alternative biomaterial to HA. ZnHA containing 1.6 wt% Zn was synthesized via a co-precipitation reaction between calcium hydroxide, orthophosphoric acid and zinc nitrate hexahydrate. Single-phase ZnHA particles with a rod-like morphology measuring ~50 nm in length and ~15 nm in width, were obtained and characterized using transmission electron microscopy and X-ray diffraction. The substitution of Zn into HA resulted in a decrease in both the a- and c-axes of the unit cell parameters, thereby causing the HA crystal structure to alter. In vitro cell culture work showed that ZnHA possessed enhanced bioactivity since an increase in the growth of human adipose-derived mesenchymal stem cells along with the bone cell differentiation markers, were observed. In addition, antibacterial work demonstrated that ZnHA exhibited antimicrobial capability since there was a significant decrease in the number of viable Staphylococcus aureus bacteria after in contact with ZnHA.



This research was supported by Hitachi Scholarship Foundation (Japan) under Research Fellowship HSF-R126.


  1. 1.
    De Groot K, Wolke J. Calcium phosphate coatings for medical implants. Proc Instn Mech Eng. 1998;212H:137–47.Google Scholar
  2. 2.
    Oonishi H. Orthopaedic applications of hydroxyapatite. Biomaterials. 1991;12:171–8.CrossRefGoogle Scholar
  3. 3.
    Oonishi H, Hench LL, Wilson J, Sugihara F, Tsuji E, Kushitani S, Iwaki H. Comparative bone growth behavior in granules of bioceramic materials of various sizes. J Biomed Mater Res. 1999;44:31–43.CrossRefGoogle Scholar
  4. 4.
    Darouiche RO. Treatment of infections associated with surgical implants. Infect Dis Clin Pract. 2004;12:258–9.Google Scholar
  5. 5.
    Yazdi M, Bernick S, Paule W, Nimni M. Postmortem degradation of demineralised bone matrix osteoinductive potential: effect of time and storage temperature. Clin Orthop Relat Res. 1991;262:281–5.Google Scholar
  6. 6.
    Thian ES, Huang J, Best SM, Barber ZH, Brooks RA, Rushton N, Bonfield W. The response of osteoblasts to nanocrystalline silicon-substituted hydroxyapatite thin films. Biomaterials. 2006;27:2692–8.CrossRefGoogle Scholar
  7. 7.
    Porter AE, Patel N, Skepper JN, Best SM, Bonfield W. Effect of sintered silicate-substituted hydroxyapatite on remodelling processes at the bone-implant interface. Biomaterials. 2004;25:3303–14.CrossRefGoogle Scholar
  8. 8.
    Patel N, Best SM, Bonfield W, Gibson IR, Hing KA, Damien E, Revell PA. A comparative study on the in vivo behavior of hydroxyapatite and silicon substituted hydroxyapatite granules. J Mater Sci Mater Med. 2002;13:1199–206.CrossRefGoogle Scholar
  9. 9.
    Chen Y, Zheng X, Xie Y, Ji H, Ding C, Li H, Dai K. Silver release from silver-containing hydroxyapatite coatings. Surf Coat Tech. 2010;205:1892–6.CrossRefGoogle Scholar
  10. 10.
    Rameshbabu N, Kumar TSS, Prabhakar TG, Sastry VS, Murty KVGK, Rao KP. Antibacterial nanosized silver substituted hydroxyapatite: synthesis and characterization. J Biomed Mater Res. 2007;80A:581–91.CrossRefGoogle Scholar
  11. 11.
    Kim TN, Feng QL, Kim JO, Wu J, Wang H, Chen GC, Cui FZ. Antimicrobial effects of metal ions (Ag+, Cu2+, Zn2+) in hydroxyapatite. J Mater Sci Mater Med. 1998;9:129–34.CrossRefGoogle Scholar
  12. 12.
    Ito A, Otsuka M, Kawamura H, Ikeuchi M, Ohgushi H, Sogo Y, Ichinose N. Zinc-containing tricalcium phosphate and related materials for promoting bone formation. Curr Appl Phys. 2005;5:402–6.CrossRefGoogle Scholar
  13. 13.
    Rossi L, Migliaccio S, Corsi A, Marzia M, Bianco P, Teti A, Gambelli L, Cianfarani S, Paoletti F, Branca F. Reduced growth plate activity and inanition. J Nutr. 2001;131:1142–6.Google Scholar
  14. 14.
    Moonga BS, Dempster DW. Zinc is a potent inhibitor of osteoclastic bone resorption in vitro. J Bone Min Res. 1995;10:453–7.CrossRefGoogle Scholar
  15. 15.
    Yamaguchi M, Oishi H, Suketa Y. Stimulatory effect of zinc on bone formation in tissue culture. Biochem Pharma. 1987;36:4007–12.CrossRefGoogle Scholar
  16. 16.
    Miyaji F, Kono Y, Suyama Y. Formation and structure of zinc-substituted calcium hydroxyapatite. Mater Res Bull. 2005;40:209–20.CrossRefGoogle Scholar
  17. 17.
    Webster TJ, Massa-Schlueter EA, Smith JL, Slamovich EB. Osteoblast response to hydroxyapatite doped with divalent and trivalent cations. Biomaterials. 2004;25:2111–21.CrossRefGoogle Scholar
  18. 18.
    Sogo Y, Ito A, Fukasawa K, Sakurai T, Ichinose N. Zinc containing hydroxyapatite ceramics to promote osteoblastic cell activity. Mater Sci Tech. 2004;20:1079–83.CrossRefGoogle Scholar
  19. 19.
    Ergun C, Webster TJ, Bizios R, Doremus RH. Hydroxylapatite with substituted magnesium, zinc, cadmium, and yttrium. I. Structure and microstructure. J Biomed Mater Res. 2002;59:305–11.CrossRefGoogle Scholar
  20. 20.
    Chung R, Hsieh M, Huang C, Perng L, Wen H, Chin T. Antimicrobial effect and human gingival biocompatibility of hydroxyapatite sol-gel coatings. J Biomed Mater Res. 2006;76B:169–78.CrossRefGoogle Scholar
  21. 21.
    Ren F, Xin R, Ge X, Leng Y. Characterization and structural analysis of zinc-substituted hydroxyapatites. Acta Biomater. 2009;5:3141–9.CrossRefGoogle Scholar
  22. 22.
    Li MO, Xiao X, Liu R, Chen C, Huang L. Structural characterization of zinc-substituted hydroxyapatite prepared by hydrothermal method. J Mater Sci Mater Med. 2008;19:797–803.CrossRefGoogle Scholar
  23. 23.
    Bigi A, Foresti E, Gandolfi M, Gazzano M, Roveri N. Inhibiting effect of zinc on hydroxyapatite crystallisation. J Inorg Biochem. 1995;58:49–58.CrossRefGoogle Scholar
  24. 24.
    LeGeros R, LeGeros J. Dense hydroxyapatite. In: Hench LL, Wilson J, editors. An introduction to bioceramics. Singapore: World Scientific; 1993. p. 139–80.CrossRefGoogle Scholar
  25. 25.
    Wang X, Ito A, Sogo Y, Li X, Oyane A. Zinc-containing apatite layers on external fixation rods promoting cell activity. Acta Biomater. 2010;6:962–8.CrossRefGoogle Scholar
  26. 26.
    Stanić V, Dimitrijević S, Antić-Stanković J, Mitrić M, Jokić B, Plećaš I, Raičević S. Synthesis, characterization and antimicrobial activity of copper and zinc-doped hydroxyapatite nanopowders. Appl Surf Sci. 2010;256:6083–9.CrossRefGoogle Scholar
  27. 27.
    Sogo Y, Sakurai T, Onuma K, Ito A. The most appropriate (Ca + Zn)/P molar ratio to minimize the zinc content of ZnTCP/HAP ceramic used in the promotion of bone formation. J Biomed Mater Res. 2002;62:457–63.CrossRefGoogle Scholar
  28. 28.
    Ito A, Ojima K, Naito H, Ichinose N, Tateishi T. Preparation, solubility, and cytocompatibility of zinc-releasing calcium phosphate ceramics. J Biomed Mater Res. 2000;50:178–83.CrossRefGoogle Scholar
  29. 29.
    Yamada Y, Ito A, Kojima H, Sakane M, Miyakawa S, Uemura T, LeGeros RZ. Inhibitory effect of Zn2+ in zinc-containing β-tricalcium phosphate on resorbing activity of mature osteoclasts. J Biomed Mater Res. 2008;84A:344–52.CrossRefGoogle Scholar
  30. 30.
    Kawamura H, Ito A, Miyakawa S, Layrolle P, Ojima K, Ichinose N, Tateishi T. Stimulatory effect of zinc-releasing calcium phosphate implant on bone formation in rabbit femoral. J Biomed Mater Res. 2000;50:184–90.CrossRefGoogle Scholar
  31. 31.
    Kay MI, Young RA, Posner AS. Crystal structure of hydroxyapatite. Nature. 1964;204:1050–2.CrossRefGoogle Scholar
  32. 32.
    Hayakawa S, Ando K, Tsuru K, Osaka A, Fujii E, Kawabata K, Bonhomme C, Babonneau F. Structural characterization and protein adsorption property of hydroxyapatite particles modified with zinc ions. J Am Ceram Soc. 2007;90:565–9.CrossRefGoogle Scholar
  33. 33.
    Rehman I, Bonfield W. Characterization of hydroxyapatite and carbonated apatite by photo acoustic FTIR spectroscopy. J Mater Sci Mater Med. 1997;8:1–4.CrossRefGoogle Scholar
  34. 34.
    Swetha M, Sahithi K, Moorthi A, Saranya N, Saravanan S, Ramasamy K, Srinivasan N, Selvamurugan N. Synthesis, characterization, and antimicrobial activity of nano-hydroxyapatite-zinc for bone tissue engineering applications. J Nanosci Nanotech. 2012;12:167–72.CrossRefGoogle Scholar
  35. 35.
    Du WL, Xu YL, Xu ZR, Fan CL. Preparation, characterization and antibacterial properties against E. coli K 88 of chitosan nanoparticle loaded copper ions. Nanotechnology. 2008;19:085707.CrossRefGoogle Scholar
  36. 36.
    Nan L, Liu Y, Lü M, Yang K. Study on antibacterial mechanism of copper-bearing austenitic antibacterial stainless steel by atomic force microscopy. J Mater Sci Mater Med. 2008;19:3057–62.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • E. S. Thian
    • 1
    • 2
  • T. Konishi
    • 2
  • Y. Kawanobe
    • 2
    • 3
  • P. N. Lim
    • 1
  • C. Choong
    • 4
  • B. Ho
    • 5
  • M. Aizawa
    • 2
    • 3
  1. 1.Department of Mechanical EngineeringNational University of SingaporeSingaporeSingapore
  2. 2.Kanagawa Academy of Science and Technology (KAST)KawasakiJapan
  3. 3.Department of Applied Chemistry, School of Science and TechnologyMeiji UniversityKawasakiJapan
  4. 4.School of Materials Science and EngineeringNanyang Technological UniversitySingaporeSingapore
  5. 5.Department of MircobiologyNational University of SingaporeSingaporeSingapore

Personalised recommendations