Article

Journal of Materials Science: Materials in Medicine

, Volume 24, Issue 2, pp 437-445

First online:

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

  • E. S. ThianAffiliated withDepartment of Mechanical Engineering, National University of SingaporeKanagawa Academy of Science and Technology (KAST) Email author 
  • , T. KonishiAffiliated withKanagawa Academy of Science and Technology (KAST)
  • , Y. KawanobeAffiliated withKanagawa Academy of Science and Technology (KAST)Department of Applied Chemistry, School of Science and Technology, Meiji University
  • , P. N. LimAffiliated withDepartment of Mechanical Engineering, National University of Singapore
  • , C. ChoongAffiliated withSchool of Materials Science and Engineering, Nanyang Technological University
  • , B. HoAffiliated withDepartment of Mircobiology, National University of Singapore
  • , M. AizawaAffiliated withKanagawa Academy of Science and Technology (KAST)Department of Applied Chemistry, School of Science and Technology, Meiji University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

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.