Multifunctional Gadolinium-Doped Mesoporous TiO₂ Nanobeads

Photoluminescence, Enhanced Spin Relaxation, and Reactive Oxygen Species Photogeneration, Beneficial for Cancer Diagnosis and Treatment

authored by

R. Imani, R. Dillert, D.W. Bahnemann, M. Pazoki, T. Apih, V. Kononenko, N. Repar, V. Kralj-Iglič, G. Boschloo, D. Drobne, T. Edvinsson, A. Iglič

Abstract

Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO

₂ sub-micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd-doped TiO

₂ exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin–lattice and spin–spin relaxation times. Density functional theory calculations show that Gd

³⁺ ions introduce impurity energy levels inside the bandgap of anatase TiO

₂, and also create dipoles that are beneficial for charge separation and decreased electron–hole recombination in the doped lattice. The Gd-doped TiO

₂ nanobeads (NBs) show enhanced ability for ROS monitored via

^•OH radical photogeneration, in comparison with undoped TiO

₂ nanobeads and TiO

₂ P25, for Gd-doping up to 10%. Cellular internalization and biocompatibility of TiO

₂@xGd NBs are tested in vitro on MG-63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation.

Organisation(s)

Institute of Technical Chemistry

Type

Article

Journal

SMALL

Volume

13

ISSN

1613-6810

Publication date

04.04.2017

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Biotechnology, Biomaterials, General Chemistry, General Materials Science

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1002/smll.201700349 (Access: Closed)