This study aimed to characterize and MRI track the mesenchymal stem cells labeled with chitosan-coated superparamagnetic iron oxide (Chitosan-SPIO). Chitosan-SPIO was synthesized from a mixture of FeCl2 and FeCl3. The human bone marrow derived mesenchymal stem cells (hBM-MSC) were labeled with 50 microg Fe/mL chitosan-SPIO and Resovist. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity, phenotype and differentiation potential. Electron microscopic observations and Prussian blue staining revealed 100% of cells were labeled with iron particles. MR imaging was able to detect the labeled MSC successfully. Chitosan-SPIO did not show any cytotoxicity up to 200 microgram Fe/mL concentration. The labeled stem cells did not exhibit any significant alterations in the surface markers expression or adipo/osteo/chondrogenic differentiation potential when compared to unlabeled control cells. After contralateral injection into rabbit ischemic brain, the iron labeled stem cells were tracked by periodical in vivo MR images. The migration of cells was also confirmed by histological studies. The novel chitosan-SPIO enables to label and track MSC for in vivo MRI without cellular alteration.
Animals ; Brain Ischemia/chemically induced/pathology/therapy ; Cell Differentiation ; Chitosan/*chemistry ; Coordination Complexes/*chemistry/toxicity ; Ferric Compounds/*chemistry ; Humans ; Magnetic Resonance Imaging ; Magnetics ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*chemistry/cytology ; Metal Nanoparticles/*chemistry ; Phenotype ; Rabbits

The hemorrhagic side effects associated with the use of clopidogrel are within the acceptable range and occur mainly at skin or gastrointestinal sites. We report a case of spontaneous spinal epidural hematoma (SSEH) in a 60-yr-old woman who was treated with clopidogrel for frequent transient ischemic attacks. To our knowledge, this is the second reported case of clopidogrel-induced SSEH. The patient's symptoms and past history of clopidogrel use suggested the diagnosis and made the procedure proceed quickly to operate SSEH 9 hr after the onset of paraplegia. The outcome was excellent. Therefore, with the popularity of antiplatelet prescription, physicians should keep in mind and urgently treat this unusual but critical side effect.
Aged ; Brain/pathology ; Cerebral Angiography ; Female ; Hematoma, Epidural, Spinal/*chemically induced ; Humans ; Ischemia/drug therapy ; Magnetic Resonance Imaging ; Platelet Aggregation Inhibitors/*adverse effects ; Ticlopidine/adverse effects/*analogs & derivatives ; Time Factors ; Treatment Outcome