Mesoscale crystallization of calcium phosphate nanostructures in protein (casein) micelles

Surachai Thachepan, Mei Li, Stephen Mann*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

15 Citations (Scopus)

Abstract

Aqueous micelles of the multi-protein calcium phosphate complex, casein, were treated at 60 degrees C and pH 7 over several months. Although partial dissociation of the micelles into 12 nm sized amorphous calcium phosphate (ACP)/protein nanoparticles occurred within a period of 14 days, crystallization of the ACP nanoclusters into bundles of hydroxyapatite (HAP) nanofilaments was not observed until after 12 weeks. The HAP nanofilaments were formed specifically within the partially disrupted protein micelles suggesting a micelle-mediated pathway of mesoscale crystallization. Similar experiments using ACP-containing synthetic micelles prepared from beta-casein protein alone indicated that co-aligned bundles of HAP nanofilaments were produced within the protein micelle interior after 24 hours at temperatures as low as 35 degrees C. The presence of Mg(2+) ions in the casein micelles, as well as a possible synergistic effect associated with the multi-protein nature of the native aggregates, could account for the marked inhibition in mesoscale crystallization observed in the casein micelles compared with the single-component beta-casein constructs.

Original languageEnglish
Pages (from-to)2400-2405
Number of pages6
JournalNanoscale
Volume2
Issue number11
DOIs
Publication statusPublished - 2010

Keywords

  • BETA-CASEIN
  • REVERSE MICROEMULSIONS
  • MEDIATED CRYSTALLIZATION
  • BLOCK-COPOLYMER
  • MILK
  • TRANSFORMATION
  • CARBONATE
  • NANOPARTICLES
  • SUPERSTRUCTURES
  • PRECIPITATION

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