TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Roeth, Anjali A.J.
A1  - Eberbeck, Dietmar
A1  - Buhl, Eva Miriam
A1  - Neumann, Ulf Peter
A1  - Schmitz-Rode, Thomas
A1  - Slabu, Ioana
T1  - Combining Bulk Temperature and Nanoheating Enables Advanced Magnetic Fluid Hyperthermia Efficacy on Pancreatic Tumor Cells
JF  - Scientific Reports
N2  - Many efforts are made worldwide to establish magnetic fluid hyperthermia (MFH) as a treatment for organ-confined tumors. However, translation to clinical application hardly succeeds as it still lacks of understanding the mechanisms determining MFH cytotoxic effects. Here, we investigate the intracellular MFH efficacy with respect to different parameters and assess the intracellular cytotoxic effects in detail. For this, MiaPaCa-2 human pancreatic tumor cells and L929 murine fibroblasts were loaded with iron-oxide magnetic nanoparticles (MNP) and exposed to MFH for either 30 min or 90 min. The resulting cytotoxic effects were assessed via clonogenic assay. Our results demonstrate that cell damage depends not only on the obvious parameters bulk temperature and duration of treatment, but most importantly on cell type and thermal energy deposited per cell during MFH treatment. Tumor cell death of 95% was achieved by depositing an intracellular total thermal energy with about 50% margin to damage of healthy cells. This is attributed to combined intracellular nanoheating and extracellular bulk heating. Tumor cell damage of up to 86% was observed for MFH treatment without perceptible bulk temperature rise. Effective heating decreased by up to 65% after MNP were internalized inside cells.
Y1  - 2018
U6  - http://dx.doi.org/10.1038/s41598-018-31553-9
SN  - 2045-2322
VL  - 8
IS  - 1
SP  - Article number 13210
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Buhl, Eva Miriam
A1  - Draack, Sebastian
A1  - Viereck, Thilo
A1  - Frank, 
A1  - Schmitz-Rode, Thomas
A1  - Slabu, Ioana
T1  - Magnetic relaxation of agglomerated and immobilized iron oxide nanoparticles for hyperthermia and imaging applications
JF  - IEEE Magnetic Letters
N2  - Magnetic nanoparticles (MNPs) are used as therapeutic and diagnostic agents for local delivery of heat and image contrast enhancement in diseased tissue. Besides magnetization, the most important parameter that determines their performance for these applications is their magnetic relaxation, which can be affected when MNPs immobilize and agglomerate inside tissues. In this letter, we investigate different MNP agglomeration states for their magnetic relaxation properties under excitation in alternating fields and relate this to their heating efficiency and imaging properties. With focus on magnetic fluid hyperthermia, two different trends in MNP heating efficiency are measured: an increase by up to 23% for agglomerated MNP in suspension and a decrease by up to 28% for mixed states of agglomerated and immobilized MNP, which indicates that immobilization is the dominant effect. The same comparatively moderate effects are obtained for the signal amplitude in magnetic particle spectroscopy.
Y1  - 2018
U6  - http://dx.doi.org/10.1109/LMAG.2018.2879034
SN  - 1949-307X
VL  - 9
IS  - Article number 8519617
PB  - IEEE
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Buhl, Eva Miriam
A1  - Baumann, Martin
A1  - Schmitz-Rode, Thomas
A1  - Slabu, Ioana
T1  - Agglomeration of magnetic nanoparticles and its effects on magnetic hyperthermia
JF  - Current Directions in Biomedical Engineering
Y1  - 2017
U6  - http://dx.doi.org/10.1515/cdbme-2017-0096
SN  - 2364-5504
VL  - 3
IS  - 2
SP  - 457
EP  - 460
PB  - De Gruyter
CY  - Berlin
ER  -