Table 2.
Alternative approaches for applying PFOB NPs to ultrasonography in vivo
| Methods to achieve US imaging | Component of the shell | Target epitope | Main points | References |
|---|---|---|---|---|
| Adaptation of ultrasonography parameters | PLGA | – | The detectability of PFOB NPs may potentially be improved using HFU | 28 |
| Lecithin and cholesterol | – | PFOB NPs provided excellent blood pool contrast images with PDHI for >1 hour | 30 | |
| PLA | – | Novel multifunctional PFOB NPs were fabricated by loading PFOB into a PLA shell followed by surface functionalization with GO and Gd-DTPA The rabbit kidney was more clearly observed in PIHI mode than in B-mode US imaging |
52 | |
| Adaptation of formulations | PLGA | – | A thinner shell produces a larger SNR and more compressible PFOB NPs PFOB NPs with a thick PLGA shell present a significant US enhancement of the blood pool during hepatic imaging |
9 |
| PLA | – | Novel multifunctional PFOB NPs were fabricated by loading PFOB and SPIO into a PLA shell followed by surface functionalization with a PEGylated gold nanoshell The kidney of the rabbit showed obvious enhancement in PIHI contrast mode |
58 | |
| PLA | – | Multifunctional PFOB NPs underwent surface functionalization with a PEGylated gold nanoshell The kidney of the rabbit showed obvious enhancement in PIHI contrast mode |
39 | |
| PLA | – | Novel multifunctional PFOB NPs were fabricated by loading PFOB intoa PLA shell followed by surface functionalization with GO and Gd-DTPA The rabbit kidney showed obvious enhancement in PIHI contrast mode |
52 | |
| PEG-PDLLA | – | All cavities of the heart, liver and kidney, particularly the horizontal axis of the right kidney, showed slight and homogeneous enhancement without any highlighted spots | 44 | |
| Fabrication of targeted UCAs | Lecithin and cholesterol | αvβ3 integrin | Specific enhanced US imaging was achieved in transgenic mice whose ears exhibited squamous metaplasia | 63 |
| Lecithin and cholesterol | FR | Images from the FR-overexpressing tumors displayed a higher intensity value than images from tumors expressing low levels of FR | 72 |
Abbreviations: FR, folate receptor; Gd-DTPA, gadolinium chelate; GO, graphene oxide; HFU, high-frequency US; PDHI, power Doppler harmonic imaging; PEG-PDLLA, poly(ethylene glycol)-b-poly(d,l-lactic acid); PFOB, perfluorooctylbromide; PFOB NPs, perfluorooctylbromide nanoparticles; PIHI, pulse inversion harmonic imaging; PLA, poly(lactic acid); PLGA, poly(lactide-co-glycolide) acid; SNR, signal-to-noise ratio; SPIO, superparamagnetic iron oxide; UCAs, US contrast agents; US, ultrasound.