Table 1.
Imaging techniques for stem cell labeling
| Goal | Strategy | Imaging modality | Labeling strategy | Cell type | Cells volume | Animals | Reference |
|---|---|---|---|---|---|---|---|
| Early cell localization and homing | Direct cell labeling methods | Optical imaging | QDs | Murine ESCs | 1×106 | Athymic nude mice | (20, 21) |
| Fluorophores | Murine ESCs | 5×106 | Gastric tumor-bearing mice | (22-24) | |||
| CPN | MSCs | 1×106 | Sprague Dawley rats | (25) | |||
| Magnetic imaging | SPIONs | Human umbilical cord MSCs | 1×106 | SCI induced rats | (26-28) | ||
| Fluorescent magnetic nanoparticles | MSCs | 3×106 | Liver cirrhosis mouse | (29) | |||
| Magneto electroporation | BMSCs | ∼1×106 | BALB/cmice | (30) | |||
| Magnetic particle imaging | SPIONs | MSCs | 5×106 ∼8×106 | Fischer 344 rats | (32) | ||
| Ferumoxytol nanoparticles | MSCs | 1×106 | C57B1/6 mice | (34) | |||
| CIONs-22s | BMSCs | ∼1×106 | BALB/cmice | (35) | |||
| Nuclear medicine imaging | 18F-FDG | MSCs | 8.5×104 | C57BL/6 mouse | (38-41) | ||
| Wistar rats | |||||||
| Indium-111 radiolabellediron oxide nanoparticles | Adipocyte-derived stem cells | 1×105 | NSG mice | (44) | |||
| Ultrasound imaging | ELS | hMSCs | 1×107 | Nude mice | (49) | ||
| TPSi NP | MSCs | 1×106 | BALB/c nude mice | (50) | |||
| GVs | Mouse MSCs | 1×107 | Arthritic rats | (51) | |||
| Long term monitering of cell viability | Indirect cell labeling methods | Optical imaging | GFP | ESCs | 5×106 | C57BL/6 mouse | (61) |
| Fluc | MSCs | 5×105 | FVB mice | (65) | |||
| MRI | Ferritin | MSCs | 2×106 | Wistar rats | (77) | ||
| Nuclear medicine imaging | D2R | hMSCs | 2.4×107 | Arthritic nude rats | (84) | ||
| NIS | MSCs | 1×106 | Athymic nude mice | (88, 89, 90-93) |
Labeling strategy for in vivo imaging methods is various depending on cell type, cell volume, animals and so on.
QDs: quantum dots, ESCs: embryonic stem cells, CPN: conjugated polymer based water-dispersible nanoparticles, MSCs: mesenchymal stem cells, SPIONs: superparamagnetic iron-oxide nanoparticles, SCI: spinal cord injury, BMSCs: bone marrow mesenchymal stem cells, CIONs-22s: cubic iron oxide nanoparticle, 18F-FDG: 2-deoxy-2-[18F]fluoro-D-glucose, NSG: non-obese diabetic/severe combined immunodeficiency/gamma, ELS: exosome-like silica nanoparticles, hMSCs: human mesenchymal stem cells, TPSi NP: cell-penetrating peptide (virus-1 transactivator of transcription) conjugated porous silicon nanoparticle, GVs: gas vesicles, GFP: green fluorescent protein, Fluc: Photinus pyralis (firefly) luciferase, MRI: magnetic resonance imaging, D2R: dopamine 2 receptor, NIS: sodium iodide symporter.