Zn doped iron oxide nanoparticles with high magnetization and photothermal efficiency for cancer treatment

Georgios Kasparis; Anouchka Plan Sangnier; Lilin Wang; Christoforos Efstathiou; Alec P LaGrow; Andreas Sergides; Claire Wilhelm; Nguyen Thi Kim Thanh

doi:10.1039/d2tb01338j

Zn doped iron oxide nanoparticles with high magnetization and photothermal efficiency for cancer treatment

J Mater Chem B. 2023 Jan 25;11(4):787-801. doi: 10.1039/d2tb01338j.

Authors

Georgios Kasparis^{1

2}, Anouchka Plan Sangnier^{3

4}, Lilin Wang^{1

2}, Christoforos Efstathiou², Alec P LaGrow^{1

2}, Andreas Sergides^{1

2}, Claire Wilhelm³, Nguyen Thi Kim Thanh^{1

2}

Affiliations

¹ Biophysics Group, Department of Physics and Astronomy, University College London, Gower street, London WC1E 6BT, UK. ntk.thanh@ucl.ac.uk.
² UCL Healthcare Biomagnetic and Nanomaterials Laboratories, 21 Albemarle street, London W1S 4BS, UK.
³ Laboratoire Physico Chimie Curie, PCC, CNRS UMR168, Institut Curie, Sorbonne University, PSL University, 75005 Paris, France.
⁴ Inserm, U1148, Laboratory for Vascular Translational Science, Université Paris 13, Sorbonne Paris Cité, Bobigny F-93017, France. claire.wilhelm@curie.fr.

Abstract

Magnetic nanoparticles (NPs) are powerful agents to induce hyperthermia in tumours upon the application of an alternating magnetic field or an infrared laser. Dopants have been investigated to alter different properties of materials. Herein, the effect of zinc doping into iron oxide NPs on their magnetic properties and structural characteristics has been investigated in-depth. A high temperature reaction with autogenous pressure was used to prepare iron oxide and zinc ferrite NPs of same size and morphology for direct comparison. Pressure was key in obtaining high quality nanocrystals with reduced lattice strain (27% less) and enhanced magnetic properties. Zn_0.4Fe_2.6O₄ NPs with small size of 10.2 ± 2.5 nm and very high saturation magnetisation of 142 ± 9 emu g_Fe+Zn^-1 were obtained. Aqueous dispersion of the NPs showed long term magnetic (up to 24 months) and colloidal stability (at least 6 d) at physiologically mimicking conditions. The samples had been kept in the fridge and had been stable for four years. The biocompatibility of Zn_0.4Fe_2.6O₄ NPs was next evaluated by metabolic activity, membrane integrity and clonogenic assays, which show an equivalence to that of iron oxide NPs. Zinc doping decreased the bandgap of the material by 22% making it a more efficient photothermal agent than iron oxide-based ones. Semiconductor photo-hyperthermia was shown to outperform magneto-hyperthermia in cancer cells, reaching the same temperature 17 times faster whilst using 20 times less material (20 mg_Fe+Zn ml^-1vs. 1 mg_Fe+Zn ml^-1). Magnetothermal conversion was minimally hindered in the cellular confinement whilst photothermal efficiency remained unchanged. Photothermia treatment alone achieved 100% cell death after 10 min of treatment compared to only 30% cell death achieved with magnetothermia at clinically relevant settings for each at their best performing concentration. Altogether, these results suggest that the biocompatible and superparamagnetic zinc ferrite NPs could be a next biomaterial of choice for photo-hyperthermia, which could outperform current iron oxide NPs for magnetic hyperthermia.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Line, Tumor
Hyperthermia, Induced* / methods
Magnetite Nanoparticles* / chemistry
Neoplasms*
Zinc / pharmacology

Substances

ferrite
ferric oxide
Magnetite Nanoparticles
Zinc