Enhanced stability of polyacrylate-coated magnetite nanoparticles in biorelevant media

Angéla Hajdú, Márta Szekeres, Ildikó Y. Tóth, Rita A. Bauer, Judith Mihály, István Zupkó, Etelka Tombácz

Research output: Contribution to journalArticle

54 Citations (Scopus)


Magnetite nanoparticles (MNPs) were prepared by alkaline hydrolysis of Fe(II) and Fe(III) chlorides. Adsorption of polyacrylic acid (PAA) on MNPs was measured at pH = 6.5 ± 0.3 and I= 0.01. M (NaCl) to find the optimal PAA amount for MNP stabilization under physiological conditions. We detected an H-bond formation between magnetite surface groups and PAA by ATR-FTIR measurements, but bonds of metal ion-carboxylate complexes, generally cited in literature, were not identified at the given pH and ionic strength. The dependence of the electrokinetic potential and the aggregation state on the amount of added PAA at various pHs was measured by electrophoretic mobility and dynamic light-scattering methods. The electrokinetic potential of the naked MNPs was low at near physiological pH, but PAA adsorption overcharged the particles. Highly negatively charged, well-stabilized carboxylated MNPs formed via adsorption of PAA in an amount of approximately ten times of that necessary to compensate the original positive charge of the magnetite. Coagulation kinetics experiments revealed gradual enhancement of salt tolerance at physiological pH from ∼0.001. M at no added PAA up to ∼0.5. M at 1.12. mmol/g PAA. The PAA-coated MNPs exert no substantial effect on the proliferation of malignant (HeLa) or non-cancerous fibroblast cells (MRC-5) as determined by means of MTT assays.

Original languageEnglish
Pages (from-to)242-249
Number of pages8
JournalColloids and Surfaces B: Biointerfaces
Publication statusPublished - Jun 1 2012


  • Carboxylated coating
  • Electrosteric stabilization
  • Magnetic fluids
  • Magnetite
  • Nanotoxicity
  • Polyacrylic acid

ASJC Scopus subject areas

  • Biotechnology
  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

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