TY  - JOUR
A1  - Brockhaus, Moritz K.
A1  - Behbahani, Mehdi
A1  - Muris, Farina
A1  - Jansen, Sebastian V.
A1  - Schmitz- Rode, Thomas
A1  - Steinseifer, Ulrich
A1  - Clauser, Johanna C.
T1  - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept
JF  - Artificial Organs
N2  - Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.
Y1  - 2021
U6  - http://dx.doi.org/10.1111/aor.14046
SN  - 1525-1594
VL  - 45
IS  - 12
SP  - 1513
EP  - 1521
PB  - Wiley
CY  - Weinheim
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  - Steinseifer, Ulrich
A1  - Kashefi, Ali
A1  - Hormes, Marcus
A1  - Schoberer, Mark
A1  - Orlikowsky, Thorsten
A1  - Behbahani, Mehdi
A1  - Behr, Marek
A1  - Schmitz-Rode, Thomas
T1  - Miniaturization of ECMO Systems : Engineering Challenges and Methods
JF  - Artificial Organs. 33 (2009), H. 5
Y1  - 2009
SN  - 1525-1594
N1  - Fifth International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion Abstracts <May 28, 2009>
SP  - A55
EP  - A55
ER  - 
TY  - JOUR
A1  - Slabu, Ioana
A1  - Roeth, Anjali A.
A1  - Engelmann, Ulrich M.
A1  - Wiekhorst, Frank
A1  - Buhl, Eva M.
A1  - Neumann, Ulf P.
A1  - Schmitz-Rode, Thomas
T1  - Modeling of magnetoliposome uptake in human pancreatic tumor cells in vitro
JF  - Nanotechnology
Y1  - 2019
U6  - http://dx.doi.org/10.1088/1361-6528/ab033e
SN  - 1361-6528
VL  - 30
IS  - 18
SP  - 184004
ER  -