Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 27th March 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 21, 2014
Previous Article Next Article

Bacterially synthesized ferrite nanoparticles for magnetic hyperthermia applications

Author affiliations


Magnetic hyperthermia uses AC stimulation of magnetic nanoparticles to generate heat for cancer cell destruction. Whilst nanoparticles produced inside magnetotactic bacteria have shown amongst the highest reported heating to date, these particles are magnetically blocked so that strong heating occurs only for mobile particles, unless magnetic field parameters are far outside clinical limits. Here, nanoparticles extracellularly produced by the bacteria Geobacter sulfurreducens are investigated that contain Co or Zn dopants to tune the magnetic anisotropy, saturation magnetization and nanoparticle sizes, enabling heating within clinical field constraints. The heating mechanisms specific to either Co or Zn doping are determined from frequency dependent specific absorption rate (SAR) measurements and innovative AC susceptometry simulations that use a realistic model concerning clusters of polydisperse nanoparticles in suspension. Whilst both particle types undergo magnetization relaxation and show heating effects in water under low AC frequency and field, only Zn doped particles maintain relaxation combined with hysteresis losses even when immobilized. This magnetic heating process could prove important in the biological environment where nanoparticle mobility may not be possible. Obtained SARs are discussed regarding clinical conditions which, together with their enhanced MRI contrast, indicate that biogenic Zn doped particles are promising for combined diagnostics and cancer therapy.

Graphical abstract: Bacterially synthesized ferrite nanoparticles for magnetic hyperthermia applications

Back to tab navigation

Supplementary files

Publication details

The article was received on 31 May 2014, accepted on 23 Aug 2014 and first published on 26 Aug 2014

Article type: Paper
DOI: 10.1039/C4NR03004D
Author version
Download author version (PDF)
Citation: Nanoscale, 2014,6, 12958-12970

  •   Request permissions

    Bacterially synthesized ferrite nanoparticles for magnetic hyperthermia applications

    E. Céspedes, J. M. Byrne, N. Farrow, S. Moise, V. S. Coker, M. Bencsik, J. R. Lloyd and N. D. Telling, Nanoscale, 2014, 6, 12958
    DOI: 10.1039/C4NR03004D

Search articles by author