Comparison of initial cell retention and clearance kinetics after subendocardial or subepicardial injections of endothelial progenitor cells in a canine myocardial infarction model.
Neither intravenous nor intracoronary routes provide targeted stem cell delivery to recently infarcted myocardium in sufficient quantities. Direct routes appear preferable. However, most prior studies have used epicardial injections, which are not practical for routine clinical use. The objective of this study was to compare cell retention and clearance kinetics between a subepicardial and a subendocardial technique.


METHODS
We evaluated 7 dogs with each technique, using (111)In-tropolone-labeled endothelial progenitor cells and serial SPECT/CT for 15 d after injection.


RESULTS
In vivo indium imaging demonstrated comparable degrees of retention: 57% +/- 15% for the subepicardial injections and 54% +/- 26% for the subendocardial injections. Clearance half-lives were also similar at 69 +/- 26 and 60 +/- 21 h, respectively.


CONCLUSIONS
This study demonstrates that subendocardial injections, clinically more practical, show clearance kinetics comparable to those of subepicardial injections and will facilitate the ultimate clinical use of this treatment modality.
Department of Medical Biophysics, University of Western Ontario, Ontario, Canada.
Andrea J
AJ
Mitchell
Eric
E
Sabondjian
Jane
J
Sykes
Lela
L
Deans
Wendy
W
Zhu
Xiangru
X
Lu
Qingping
Q
Feng
Frank S
FS
Prato
Gerald
G
Wisenberg
D000818:Animals; D002454:Cell Differentiation; D004195:Disease Models, Animal; D004285:Dogs; D004699:Endocardium; D042783:Endothelial Cells / Q000166:cytology* / Q000637:transplantation; D005260:Female; D006207:Half-Life; D007267:Injections / Q000379:methods*; D008657:Metabolic Clearance Rate; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000601:surgery*; D009942:Organometallic Compounds; D010496:Pericardium; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014334:Tropolone / Q000031:analogs & derivatives
D009942:Organometallic Compounds; C043895:indium tris(tropolonate); D014334:Tropolone