Revisiting whitlockite, the second most abundant biomineral in bone: Nanocrystal synthesis in physiologically relevant conditions and biocompatibility evaluation

Hae Lin Jang, Kyoungsuk Jin, Jaehun Lee, Younghye Kim, Seung Hoon Nahm, Kug Sun Hong, Ki Tae Nam

Research output: Contribution to journalArticlepeer-review

92 Citations (Scopus)

Abstract

The synthesis of pure whitlockite (WH: Ca18Mg 2(HPO4)2(PO4)12) has remained a challenge even though it is the second most abundant inorganic in living bone. Although a few reports about the precipitation of WH in heterogeneous phases have been published, to date, synthesizing WH without utilizing any effects of a buffer or various other ions remains difficult. Thus, the related research fields have encountered difficulties and have not been fully developed. Here, we developed a large-scale synthesis method for pure WH nanoparticles in a ternary Ca(OH)2-Mg(OH)2-H 3PO4 system based on a systematic approach. We used excess Mg2+ to impede the growth of hydroxyapatite (HAP: Ca 10(PO4)6(OH)2) and the formation of other kinetically favored calcium phosphate intermediate phases. In addition, we designed and investigated the synthesis conditions of WH under the acidic pH conditions required to dissolve HAP, which is the most thermodynamically stable phase above pH 4.2, and to incorporate the HPO42- group into the chemical structure of WH. We demonstrated that pure WH nanoparticles can be precipitated under Mg2+-rich and acidic pH conditions without any intermediate phases. Interestingly, this synthesized nano-WH showed comparable biocompatibility with HAP. Our methodology for determining the synthesis conditions of WH could provide a new platform for investigating other important precipitants in aqueous systems.

Original languageEnglish
Pages (from-to)634-641
Number of pages8
JournalACS nano
Volume8
Issue number1
DOIs
Publication statusPublished - 2014 Jan 28
Externally publishedYes

Keywords

  • biomaterial
  • biomineralization
  • bone growth
  • calcium phosphate
  • inorganic synthesis
  • nanoparticle
  • whitlockite

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Fingerprint

Dive into the research topics of 'Revisiting whitlockite, the second most abundant biomineral in bone: Nanocrystal synthesis in physiologically relevant conditions and biocompatibility evaluation'. Together they form a unique fingerprint.

Cite this