Nanomaterials (May 2018)

Iron Oxide Colloidal Nanoclusters as Theranostic Vehicles and Their Interactions at the Cellular Level

  • Athanasia Kostopoulou,
  • Konstantinos Brintakis,
  • Eirini Fragogeorgi,
  • Amalia Anthousi,
  • Liberato Manna,
  • Sylvie Begin-Colin,
  • Claire Billotey,
  • Anthi Ranella,
  • George Loudos,
  • Irene Athanassakis,
  • Alexandros Lappas

DOI
https://doi.org/10.3390/nano8050315
Journal volume & issue
Vol. 8, no. 5
p. 315

Abstract

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Advances in surfactant-assisted chemical approaches have led the way for the exploitation of nanoscale inorganic particles in medical diagnosis and treatment. In this field, magnetically-driven multimodal nanotools that perform both detection and therapy, well-designed in size, shape and composition, are highly advantageous. Such a theranostic material—which entails the controlled assembly of smaller (maghemite) nanocrystals in a secondary motif that is highly dispersible in aqueous media—is discussed here. These surface functionalized, pomegranate-like ferrimagnetic nanoclusters (40–85 nm) are made of nanocrystal subunits that show a remarkable magnetic resonance imaging contrast efficiency, which is better than that of the superparamagnetic contrast agent Endorem©. Going beyond this attribute and with their demonstrated low cytotoxicity in hand, we examine the critical interaction of such nanoprobes with cells at different physiological environments. The time-dependent in vivo scintigraphic imaging of mice experimental models, combined with a biodistribution study, revealed the accumulation of nanoclusters in the spleen and liver. Moreover, the in vitro proliferation of spleen cells and cytokine production witnessed a size-selective regulation of immune system cells, inferring that smaller clusters induce mainly inflammatory activities, while larger ones induce anti-inflammatory actions. The preliminary findings corroborate that the modular chemistry of magnetic iron oxide nanoclusters stimulates unexplored pathways that could be driven to alter their function in favor of healthcare.

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