Bioinspired Citrate-Apatite Nanocrystals Doped with Divalent Transition Metal Ions

Research output: Contribution to journalArticle

Abstract

Bioinspired citrate-carbonate-apatite (cAp) nanocrystals doped with divalent transition metal (M) ions, i.e., Mn2+, Co2+, and Ni2+, were prepared by batch thermal decomplexing of Ca2+/M/citrate/phosphate/carbonate solutions at 80 and 37 degrees C, with initial Ca2+/M molar ratios of 9:1 and 5:5, and at different crystallization times ranging from 1 to 96 h. A thorough chemical, crystallographic, and morphological characterization was carried out on the doped nanocrystals revealing that (i) using similar crystallization conditions the amount of incorporated M normally followed the order Mn2+ > Co2+ > Ni2+; (ii) the growth of nano crystals was clearly enhanced at 80 degrees C and when a lower amount of M was incorporated in the crystal structure; (iii) the increase of the M content increased the aspect ratio (length/width) of the M-doped cAp nanocrystals compared to undoped ones, (iv) the incorporation of the 6.5 wt % of M is a threshold for the long-range order of the nano crystal; in fact, with a higher M content, amorphous materials were mainly produced. Additionally, we found that citrate controlled the activity of hydrated M ions in solution, the extension of the doping process, and protected the M ions against oxidation in solution as well as in the outermost layer of doped nanocrystals. Preliminary in vitro cytotoxicity studies on the murine MS1 endothelial cell line showed that the produced Mn2+- and Co2+-doped nanocrystals were highly biocompatible at doses comparable to those of undoped ones, with the exception of the nanocrystals substituted with the highest Co2+ content at the higher doses.

Details

Authors
  • Francisco Martinez
  • Michele Iafisco
  • Jose Manuel Delgado-Lopez
  • Carla Martinez-Benito
  • Catalina Ruiz-Perez
  • Donato Colangelo
  • Francesca Oltolina
  • Maria Prat
  • Jaime Gomez-Morales
Organisations
External organisations
  • CSIC Andalusian Institute of Earth Sciences (IACT)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Nano Technology
Original languageEnglish
Pages (from-to)145-153
JournalCrystal Growth & Design
Volume16
Issue number1
Publication statusPublished - 2016
Publication categoryResearch
Peer-reviewedYes