B.Sc., Ph.D. (Newcastle).

Tel: 0116 252 2109

email: mplowe@le.ac.uk

Research Interests

Our research interests are in the field of Medicinal Inorganic Chemistry. In particular the chemistry of complexes of the lanthanides, such as gadolinium for use as contrast agents in Magnetic Resonance Imaging (MRI), europium and terbium as luminescent sensors. In particular we are developing high-relaxivity and responsive or ‘activated’ MR contrast agents for molecular imaging applications. We are also interested in the use of radioisotopes of certain lanthanides and group 13 metals in diagnostic and therapeutic nuclear medicine.
Current topics that are occupying our time:

• Development of dual mode MR-optical and MR-PET agents.
• Application of Cu(I) catalysed ‘click’ chemistry in alkyne-appended Ln(III) complexes.
• Synthesis of fluorescent probes for Zn(II).

Click Chemistry With Lanthanide Complexes: A Word Of Caution

A propargyl-appended Eu(III) complex shows unanticipated reactivity towards NaN₃ in the Cu(I) catalysed click reaction yielding an unsubstituted 1,2,3-triazole. The resulting complex exhibits pH-responsive ¹H NMR and Eu(III) luminescence behaviour in the physiological pH range consistent with deprotonation of the NH-acidic bound triazole.

Dalton Trans. 2009, 9725-9727; Dalton Trans. 2009, 6283-6285.

An Esterase-Activated Magnetic Resonance Contrast Agent

A Gd(III) complex bearing pendant acetoxymethyl esters is activated on exposure to porcine liver esterase; the 84% increase in relaxivity is a result of suppression of HCO₃^-/CO₃^2- binding by the resulting negative charge.

Chem. Commun., 2007, 4044-4046; Inorg. Chem. 2009, 48, 8515–8522.

New Contrast Agents For Magnetic Resonance Angiography

On binding to human serum albumin (HSA), the Eu(III) luminescent emission enhancement of a complex containing a binaphthyl chromophore enables the determination of binding constants, showing no chiral discrimination for the (R)-(K = 8200 ± 810 M^-1) and (S)-enantiomers (K = 7710 ± 460 M^-1).

Chem. Commun., 2005, 657-659; ChemPhysChem, 2006, 7, 1590-1597; Inorg. Chem., 2007, 46, 3576-3584.

 Recent Publications

1. Stasiuk, G. J., Lowe M. P. ,"Click chemistry with lanthanide complexes:  a word of caution", Dalton Trans., 2009, 9725-9727.
2. Giardiello, M.; Lowe, M. P. “Luminescence Study of Eu(III) Analogues of Esterase-Activated Magnetic Resonance Contrast Agents”, Inorg. Chem. 2009, 48, 8515–8522.
3. Jauregui, M.; Perry, W. S.; Allain, C.; Vidler, L. R.; Willis, M. C.; Kenwright, A. M.; Snaith, J. S.; Stasiuk, G. J.; Lowe, M. P.; Faulkner, S. “Changing the local coordination environment in mono- and bi- nuclear lanthanide complexes through click chemistry”, Dalton Trans. 2009, 6283-6285.
4. von Haeften, K.; Binns, C.; Brewer, A.; Crisan, O.; Howes, P. B.; Lowe, M. P.; Sibbley-Allen, C.; Thornton, S. C. “A novel approach towards the production of luminescent silicon nanoparticles: sputtering, gas aggregation and co-deposition with H₂O”, Eur. Phys. J. D 2009, 52, 11-14.
5. Giardiello, M.; Lowe, M. P. and Botta, M. “An Esterase-activated Magnetic Resonance Contrast Agent”, Chem. Commun., 2007, 4044-4046.
6. Zech, S. G.; Eldredge, H. B.; Lowe, M. P. and Caravan, P. “Protein Binding to Lanthanide(III) Complexes Can Reduce the Water Exchange Rate at the Lanthanide”, Inorg. Chem., 2007, 46, 3576-3584.
7. Raitsimring, A. M.; Astashkin, A. V.; Baute, D.; Goldfarb, D.; Poluektov, O. G.; Lowe, M. P.; Zech, S. G.; Caravan, P., “Determination of the Hydration Number of Gadolinium (III) Complexes by High-Field Pulsed 17O ENDOR Spectroscopy”, Chem. Phys. Chem., 2006, 7, 1590-1597