A Frequency-Selective pH-Responsive paraCEST Agent.
Angew Chem Int Ed Engl
; 59(48): 21671-21676, 2020 11 23.
Article
en En
| MEDLINE
| ID: mdl-32726500
ABSTRACT
Paramagnetic chemical exchange saturation transfer (paraCEST) agents are well-suited for imaging tissue pH because the basis of CEST, chemical exchange, is inherently sensitive to pH. Several previous pH-sensitive paraCEST agents were based on an exchanging Ln3+ -bound water molecule as the CEST antenna but this design often added additional line-broadening to the bulk water signal due to T2 exchange. We report herein a pH-sensitive paraCEST agent that lacks an inner-sphere water molecule but contains one Ln-bound -OH group for CEST activation. The Yb3+ complex, Yb(1), displayed a single, highly shifted CEST peak originating from the exchangeable Yb-OH proton, the frequency of which changed over the biologically relevant pH range. CEST images of phantoms ranging in pH from 6 to 8 demonstrate the potential of this agent for imaging pH. Initial rodent imaging studies showed that Gd(1) remains in the vascular system much longer than anticipated but is cleared slowly via renal filtration.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Medios de Contraste
/
Elementos de la Serie de los Lantanoides
/
Sustancias Luminiscentes
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Complejos de Coordinación
Límite:
Animals
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos