Effect of precursor deficiency induced ca/p ratio on antibacterial and osteoblast adhesion properties of ag-incorporated hydroxyapatite: Reducing ag toxicity

Ozkan Gokcekaya, Celaletdin Ergun*, Thomas J. Webster, Abdurrahman Bahadir, Kyosuke Ueda, Takayuki Narushima, Takayoshi Nakano

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Ag-containing hydroxyapatite (HA) can reduce risks associated with bacterial infections which may eventually require additional surgical operations to retrieve a failed implant. The biologi-cal properties of HA in such applications are strongly affected by its composition in terms of dopants as well as Ca/P stoichiometry, which can be easily controlled by altering processing parameters, such as precursor concentrations. The objective of this in vitro study was to understand the effect of variations in HA precursor solutions on antibacterial properties againstEscherichia coli (E. coli) and for promoting osteoblast (bone-forming cell) adhesion on Ag incorporated HA (AgHA) which has not yet been investigated. For this, two groups of AgHAs were synthesized via a precipitation method by adjusting precursor reactants with a stoichiometric value of 1.67, being either (Ca + Ag)/P (Ca-deficient) or Ca/(P + Ag) (P-deficient), and were characterized by XRD, FTIR, and SEM-EDS. Results showed that Ag+ incorporated into the Ca2+ sites was associated with a corresponding OH vacancy. Additional incorporation of CO32− into PO43− sites occurred specifically for the P-deficient AgHAs. While antibacterial properties increased, osteoblast adhesion decreased with increasing Ag content for the Ca-deficient AgHAs, as anticipated. In contrast, significant antibacterial properties with good osteoblast behavior were observed on the P-deficient AgHAs even with a lower Ag content, owing to carbonated HA. Thus, this showed that by synthesizing AgHA using P-deficient precursors with carbonate substitution, one can keep the antibacterial properties of Ag in HA while reducing its toxic effect on osteoblasts.

Original languageEnglish
Article number3158
Issue number12
Publication statusPublished - 2 Jun 2021

Bibliographical note

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.


Funding: This research was financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK Contract No: 106M053) and the Japan Society for the Promotion of Science (Contract No: 201500660).

FundersFunder number
Japan Society for the Promotion of Science201500660
Türkiye Bilimsel ve Teknolojik Araştirma Kurumu


    • Antibacterial
    • Carbonate
    • Hydroxyapatite
    • Incorporation
    • Osteoblast adhesion
    • Silver


    Dive into the research topics of 'Effect of precursor deficiency induced ca/p ratio on antibacterial and osteoblast adhesion properties of ag-incorporated hydroxyapatite: Reducing ag toxicity'. Together they form a unique fingerprint.

    Cite this