Abstract for presentation at 38th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine 2008

Cytotoxicity of 111In-oxine on Mesenchymal Stem Cells: A Time Dependent Adverse Effect

  • Dr Ali Gholamrezanezhad, Research Institute for Nuclear Medicine; Medical Science of Tehran University, Iran
  • Dr Sahar Mirpour, Research Institute for Nuclear Medicine, Medical Science of Tehran University, Iran
  • Dr Mohammad Bagheri, Research Institute for Gastrointestinal diseases; Medical Science of Tehran University, Iran
  • Dr Reza Malekzadeh, Digestive Diseases Research Center; Medical Science of Tehran University, Iran
  • Dr Sarah Yarmand, Shariati Hospital/Tehran University of Medical Sciences, Iran

    • Labeling with 111In-tracers has been among the most widely used methods for stem cell tracking. Theoretically it is possible that viability of these cells within 2-weeks (5half-lives) after labeling to be negatively affected by 111In-tracers (even if the cell viability in first day of labeling is unaffected). So, we continuously followed influence of 111In labeling on stem cell viability during the 2 week period of post-labeling. Method: After culturing mesenchymal stem cells (MSCs), we divided them into 6samples, each of which contained 1000000MSCs. The first sample (control) was not radiolabeled with 111 In-Oxine and handled identical to other five samples. The remaining five samples (samples 2 to 6) were labeled with following doses of 111In-oxine, respectively: 0.92MBq,1.85MBq,3.7MBq, 5.55MBq, 7.4MBq. For evaluating effects of 111In-Oxine labeling on cellular viability and count, samples were examined immediately after labeling(3hr),24hr,48hr,5th,7th and 14th days post-labeling. Results: There was no significant relation between labeling efficiency and administered dose. The associations between specific activity and radiotracer dosage was significant(P=0.001,r=0.9). A negative correlation was noted between radiotracer dosage and viability during the 2-week period.Conclusion: Cytotoxic effects of 111In on stem cells is time-dependent. Hence, assessment of viability immediately after labeling (which is frequently performed in clinical trials) is unable to detect adverse effects of 111-In on stem cells. Even low doses of 111In-oxine is accompany with significant cell loss within two-week. We recommend not using 111In-oxine routinely in stem cell therapies, and if necessary, as low as possible of 111In-oxine should be used to minimize cell loss.

    Conference Organiser - ICMS Pty Ltd