Crystallization of bioinspired citrate-functionalized nanoapatite with tailored carbonate content

José Manuel Delgado-López, Michele Iafisco, Isaac Rodríguez, Anna Tampieri, María Prat, Jaime Gómez-Morales

Research output: Contribution to journalArticlepeer-review

122 Scopus citations


Novel citrate-functionalized carbonate-apatite nanoparticles with mean lengths ranging from 20 to 100 nm were synthesized by a thermal-decomplexing batch method. Needle-like and plate-shaped morphologies were obtained in the absence and presence of sodium carbonate in the precipitation medium, respectively. The precipitation time and the presence of sodium carbonate strongly affect the chemical composition as well as the dimensions and the crystallinity of nanoparticles. At a short precipitation time, poorly crystalline apatites of 100 nm mean length with a low degree of carbonation (1.5% w/w, mainly in B-position) and a high citrate content (5.9% w/w) were precipitated. This citrate content is close to that recently measured in bone apatite. When increasing the precipitation time up to 96 h the mean length and the citrate content progressively decrease and at the same time the nanoparticles become more crystalline. They are composed of a well-ordered carbonate-substituted apatitic core embedded in a non-apatitic hydrated layer containing citrate ions. This layer progressively transforms into a more stable apatite domain upon maturation in aqueous media. The nanoparticles displayed excellent compatibility properties in cell biological systems, since they were not cytotoxic to a mouse carcinoma cell line when added to a final concentration of 100 μg ml-1. This work provides new insights into the role of citrate on the crystallization of nanoapatites. Moreover, the synthesized nanoparticles are promising materials for use as nanocarriers for local targeted drug delivery systems as well as building blocks for the preparation of nanostructured scaffolds for cells in bone tissue engineering.

Original languageEnglish (US)
Pages (from-to)3491-3499
Number of pages9
JournalActa Biomaterialia
Issue number9
StatePublished - Sep 2012


  • Calcium phosphates
  • Carbonate
  • Citrate
  • Hydroxyapatite
  • Nanocrystals

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering
  • Biotechnology
  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Crystallization of bioinspired citrate-functionalized nanoapatite with tailored carbonate content'. Together they form a unique fingerprint.

Cite this