Development of a method for magnetic labeling of platelets.
Platelets play a dominant role in the pathogenesis of bleeding disorders and cardiovascular pathology (e.g., myocardial infarction). Nonradioactive labeling of platelets may offer several clinical applications, ranging from survival studies of transfused platelet concentrates to studies on the pathogenesis of stroke. We used ferucarbotran superparamagnetic nanoparticles (NPs) for cell labeling. Platelets incorporated these NPs by endocytosis (without linkers or binding agents). Flow cytometry using FITC-conjugated magnetic NPs showed ex vivo labeling of about 98% of platelets; NPs were predominantly located inside the platelet granules as confirmed by fluorescence microscopy and transmission electron microscopy. Iron concentrations of 2 pg per platelet were reached as determined by atomic absorption spectroscopy. This will enable sensitive ex vivo determination of transfused labeled platelets, allowing survival studies. In vitro, labeled platelets gave a clear signal by 7 Tesla magnetic resonance tomography. Magnetic labeling of platelets may offer a new tool for diagnosis and research in transfusion medicine and cardiovascular medicine.


BACKGROUND
In this study a platelet labeling method is discussed and described for in vivo and ex vivo applications, using a binder or linker free fluorescent superparamagnetic iron nanoparticle system. Magnetic labeling of platelets may offer a new tool for diagnosis and research in transfusion medicine and cardiovascular medicine.
Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Germany. aurich@uni-greifswald.de
Konstanze
K
Aurich
Mark-Christopher
MC
Spoerl
Birgitt
B
Fürll
Rabea
R
Sietmann
Andreas
A
Greinacher
Norbert
N
Hosten
Werner
W
Weitschies
D001792:Blood Platelets / Q000737:chemistry*; D058948:Cell Tracking / Q000379:methods*; D003911:Dextrans / Q000737:chemistry*; D004705:Endocytosis; D005290:Ferric Compounds / Q000737:chemistry; D006801:Humans; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D013194:Staining and Labeling
D003911:Dextrans; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; C065507:ferumoxides