Effect of magnetic nanoparticle heating on cortical neuron viability.
OBJECTIVE
Superparamagnetic iron oxide nanoparticles are currently approved for use as an adjunctive treatment to glioblastoma multiforme radiotherapy. Radio frequency stimulation of the nanoparticles generates localised hyperthermia, which sensitises the tumour to the effects of radiotherapy. Clinical trials reported thus far are promising, with an increase in patient survival rate; however, what are left unaddressed are the implications of this technology on the surrounding healthy tissue.


METHODS
Aminosilane-coated iron oxide nanoparticles suspended in culture medium were applied to chick embryonic cortical neuron cultures. Cultures were heated to 37 °C or 45 °C by an induction coil system for 2 h. The latter regime emulates the therapeutic conditions of the adjunctive therapy. Cellular viability and neurite retraction was quantified 24 h after exposure to the hyperthermic events.


RESULTS
The hyperthermic load inflicted little damage to the neuron cultures, as determined by calcein-AM, propidium iodide, and alamarBlue® assays. Fluorescence imaging was used to assess the extent of neurite retraction which was found to be negligible.


CONCLUSIONS
Retention of chick, embryonic cortical neuron viability was confirmed under the thermal conditions produced by radiofrequency stimulation of iron oxide nanoparticles. While these results are not directly applicable to clinical applications of hyperthermia, the thermotolerance of chick embryonic cortical neurons is promising and calls for further studies employing human cultures of neurons and glial cells.
Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York and.
Christopher J
CJ
Rivet
Yuan
Y
Yuan
Ryan J
RJ
Gilbert
Diana-Andra
DA
Borca-Tasciuc
D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D002642:Chick Embryo; D005290:Ferric Compounds / Q000008:administration & dosage*; D005625:Frontal Lobe / Q000166:cytology / Q000196:embryology; D006358:Hot Temperature; D006979:Hyperthermia, Induced; D060328:Magnetic Phenomena; D053758:Nanoparticles / Q000008:administration & dosage*; D009474:Neurons / Q000528:radiation effects*
D005290:Ferric Compounds; C000499:ferric oxide