Non-invasive analysis of myoblast transplants in rodent cardiac muscle.
BACKGROUND
Magnetic resonance imaging (MRI) of magnetically labeled stem cells is a non-invasive approach that can provide images with high spatial resolution. We evaluated the ability of a commercially available, Food and Drug Administration (FDA) approved contrast agent to allow the monitoring of myoblast transplants in the rodent heart.


RESULTS
Primary rat myoblasts were efficiently labeled by incubation with ferumoxide-polycation complexes and labeled cells retained their normal capacity to generate mature myotubes. Intra-cellular iron-oxide accumulation resulted in MRI contrast changes, allowing for three-dimensional, non-invasive detection of labeled cells in the rodent myocardium. Histological analysis of hearts injected with labeled myoblasts or control, non-viable myoblasts revealed that areas of MRI contrast changes corresponded to iron contained within engrafted myotubes and scavenger cells up to two months post-injection.


CONCLUSIONS
The high sensitivity of MR imaging will allow for non-invasive studies of cardiac stem cell migration and homing. Additional techniques are in development to non-invasively determine stem cell engraftment rates, viability and differentiation.
Cahill
Kevin S
KS
Powell Gene Therapy Center, University of Florida, Gainesville 32610, USA
Germain
Sean
S
Byrne
Barry J
BJ
Walter
Glenn A
GA
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003287:Contrast Media; D005260:Female; D052203:Ferrosoferric Oxide; D006085:Graft Survival / Q000502:physiology; D021621:Imaging, Three-Dimensional / Q000379:methods; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D032386:Myoblasts, Cardiac / Q000637:transplantation*; D009206:Myocardium / Q000166:cytology*; D010087:Oxides; D011107:Polylysine; D051381:Rats; D011917:Rats, Inbred Lew
D003287:Contrast Media; D010087:Oxides; D011107:Polylysine; D007501:Iron; D052203:Ferrosoferric Oxide