title: Long-term in vivo magnetic resonance imaging tracking of endothelial progenitor cells transplanted in rat ischemic limbs and their angiogenic potential.
abstract: Stem cell therapy has been used to repair ischemic tissues in the limbs, in myocardial infarctions, and in the brain. To understand the mechanisms of healing, a contrast agent capable of inducing sufficient magnetic resonance (MR) contrast would be useful in providing fundamental information about the cell migration and incorporation into the ischemic tissue. A magnetic resonance imaging contrast agent composed of dextran and gadolinium chelate was synthesized. Hydroxyl groups of dextran were activated with 1,1'-carbonylbis-1H-imidazole and reacted with propanediamine to obtain aminated dextran. This modified polymer was then reacted with mono-N-succinimidyl 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate, then with fluorescein isothiocyanate, and finally reacted with gadolinium chloride solution (Dex-DOTA-Gd3(+)). Endothelial progenitor cells (EPCs) were selected as a stem cell model for magnetic resonance imaging tracking. Cells were isolated from the bone marrow harvested from the femurs and tibias of rats. Dex-DOTA-Gd3(+) was then introduced into the EPCs by electroporation. The intracellular stability and cytotoxicity of Dex-DOTA-Gd3(+) were evaluated in vitro. Dex-DOTA-Gd3(+)-labeled EPCs were transplanted into a rat model of ischemic limb, and MR images were acquired. Dex-DOTA-Gd3(+) was found to efficiently label EPCs over a long duration without significant cytotoxicity. This provides an MR signal sufficient for tracking the EPCs intramuscularly injected into the limb.
authors.affiliation: Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Agudelo
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Tachibana
authors.forename: Teramoto
authors.initials: T
authors.lastname: Noboru
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Iida
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yamaoka
mesh_terms: D000818:Animals; D002469:Cell Separation; D002470:Cell Survival; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry; D003911:Dextrans / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology*; D005121:Extremities / Q000098:blood supply* / Q000473:pathology; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D007150:Immunohistochemistry; D007511:Ischemia / Q000473:pathology / Q000628:therapy*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D018919:Neovascularization, Physiologic; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010641:Phenotype; D051381:Rats; D011916:Rats, Inbred F344; D013194:Staining and Labeling; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology* / Q000201:enzymology; D013997:Time Factors
chemical_list: D003287:Contrast Media; D003911:Dextrans; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; D007770:L-Lactate Dehydrogenase