TY - JOUR

T1 - Multifunctional Gadolinium-Doped Mesoporous TiO2 Nanobeads

T2 - Photoluminescence, Enhanced Spin Relaxation, and Reactive Oxygen Species Photogeneration, Beneficial for Cancer Diagnosis and Treatment

AU - Imani, R.

AU - Dillert, R.

AU - Bahnemann, D.W.

AU - Pazoki, M.

AU - Apih, T.

AU - Kononenko, V.

AU - Repar, N.

AU - Kralj-Iglič, V.

AU - Boschloo, G.

AU - Drobne, D.

AU - Edvinsson, T.

AU - Iglič, A.

N1 - Funding information: M.P., T.A., V.K., and N.R. contributed equally to this work. The authors wish to acknowledge the Slovenian Research Agency (ARRS) grants J1-6728 and P2-0232 for the financial support in carrying out this research. The authors would like to thank Dr. Leif Häggman in Uppsala University for support in the SEM and EDAX measurements, Prof. Igor Serša in Jozef Stefan Institute for his handful help MRI measurements, and Prof. Andreja Erman in Cell Biology Institute, Slovenia, for her assistance in TEM imaging of cells. The authors acknowledge Uppsala Multidisciplinary Centre for Advanced Computational Science (UPPMAX) for providing the computational resources under Projects snic2015-6-65.

PY - 2017/4/4

Y1 - 2017/4/4

N2 - 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.

AB - 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.

KW - TiO

KW - cancer treatment

KW - gadolinium

KW - photocatalysis

KW - reactive oxygen species

UR - http://www.scopus.com/inward/record.url?scp=85017339970&partnerID=8YFLogxK

U2 - 10.1002/smll.201700349

DO - 10.1002/smll.201700349

M3 - Article

VL - 13

JO - SMALL

JF - SMALL

SN - 1613-6810

IS - 20

M1 - 1700349

ER -