Table 1 Examples of optoacoustic contrast agents used for in vivo/ex vivo stem cell tracking
From: Contrast agents for photoacoustic imaging: a review of stem cell tracking
Contrast agent in use | Surface Coating utilised | Opto-acoustic excitation wavelength (nm) | Intracellular concentration | Number of days of longitudinal tracking | Number of cells imaged | Imaging Modalities utilised | Stem cell-based application |
|---|---|---|---|---|---|---|---|
ICG | Â | 810 | 0.25 mg/ml | 3 days | 3\(\times 10^5\) cells | OAI | Cell transplantation based therapies [31] |
PBP | Citrate | 701 | 0.2 mg/ml | 15 days | \(10^6\) cells | OAI | Traumatic brain injury [40] |
PBNP | Poly-L-lysine (PLL) | 730 | 50 \(\upmu\)g/ml | 14 days | 5\(\times 10^4\) cells | OAI | Ischemic brain damage [32] |
AuNS | Â | 700 | 1.5 ng gold/cell | Â | 1000 cells/\(\upmu\)l | OAI | Neuro degenerative diseases [70] |
| Â | 700 | 200Â \(\upmu\)g gold/ml | Â | 5\(\times 10^6\) cells | OAI | Stem cell delivery trabecular meshwork to treat glaucoma [49] | |
Gold nanotracer (Au NT) | PLL | 700 | [4.53\(\pm\) 0.04]\(\times 10^5\) Au NTs/cell | 10 days | 5\(\times 10^4\) cells | OAI | Ischemic heart disease [42] |
Iron oxide nanoparticle | PLGA | 532, 700 | 20 \(\upmu\)g/ml | Â | Â | OAI | Delivery of resveratrol [33] |
GNR | Silica | 680 | 1.5\(\times 10^6\) SiGNRs/cell | 4 days | \(10^5\) cells | OAI | Muscular dystrophy [37] |
Silica | 760 | 3.5\(\times 10^{-2}\) \(\upmu\)g Au/ml | 15 days | 2\(\times 10^4\) cells | OAI | In vivo stem cell tracking [38] | |
IR775c | 790, 920 | 20 \(\upmu\)g/ml | 10 days | \(10^7\) cells/ml | OAI | Stem cell viability tracking [61] | |
OSPN\(^+\) | PLL | 916, 1025 | 50 \(\upmu\)g/ml | 14 days | \(10^5\) cells | OAI | In vivo stem cell tracking [44] |
PANP | Â | 705 | 4 nM | Â | 2000 cells | OAI | To track embryonic stem-cell derived cardiomyocytes [36] |
SPIO@Au | Gold | 810 | 4 \(\upmu\)g/ml | 3 days | \(10^6\) cells | OAI, MRI | MSC mediated brain lesion treatment [67] |
AuNC | Â | 800 | 2.3\(\times 10^4\) AuNCs/ cell | Â | \(10^5\) cells | OAI, Two-photon microscopy | In vivo stem cell tracking [51] |
Gd(III)-SMNP |  | 720–760 | 0.43 mg/ml |  | 5\(\times 10^5\) cells | OAI, MRI | In vivo stem cell tracking [68] |
Iron oxide nanobubbles labelled with DiR | PLGA | Â | 240 \(\upmu\)g/ml | 3 days | \(10^5\) cells | US, OAI, MPI | Cardiac stem cell therapy [73] |
Fe\(^{3+}\)-PEG-MNP | Â | Â | 800 \(\upmu\)g/ml | 35 days | 2\(\times 10^6\) cells | OAI, MRI | In vivo stem cell tracking [45] |