AI Article Synopsis
- Paramagnetic chemical exchange saturation transfer (paraCEST) agents are ideal for imaging tissue pH due to their sensitivity to changes in pH through chemical exchange.
- The new pH-sensitive paraCEST agent developed lacks an inner-sphere water molecule and instead uses a Yb-bound -OH group, providing a distinct CEST peak that correlates with varying pH levels.
- Initial rodent studies indicate that the Gd(1) complex has a prolonged presence in the bloodstream but is eventually cleared slowly through the kidneys.
Article 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 Ln -bound water molecule as the CEST antenna but this design often added additional line-broadening to the bulk water signal due to T 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 Yb 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.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7719596 | PMC |
| http://dx.doi.org/10.1002/anie.202008888 | DOI Listing |
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