High sensitivity lanthanide(III) based probes for MR-medical imaging

Size-Induced Enhancement of Chemical Exchange Saturation Transfer (CEST) Contrast in Liposomes

“…In this regard, conjugation chemistry approaches that have been used for Gd(III) chelate-based imaging applications may be applied to new CEST agents to improve their ability to reach the desired target. 3 Finally, CEST agents whose resonance frequencies are close to water require additional effort in pulse sequence optimization and data analysis. The optimum presaturation pulse power and duration should be determined experimentally to ensure high saturation efficiency of the agent and low direct saturation of the bulk water.…”

“…Thulium 1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane (TmDOTA) was synthesized by the complexation of DOTA with Tm(OH) 3 . 23 TmCl 3 (Sigma-Aldrich, Milwaukee, WI) was converted to Tm(OH) 3 by adding 3 equiv of NaOH in water.…”

“…23 TmCl 3 (Sigma-Aldrich, Milwaukee, WI) was converted to Tm(OH) 3 by adding 3 equiv of NaOH in water. The solid formed was washed with water until the pH decreased to 8.…”

“…The solid formed was washed with water until the pH decreased to 8. DOTA was added to the suspension of Tm(OH) 3 in water, and the solution was stirred overnight with the pH at 6. The solution was then heated to 60 °C for 24 h to ensure complete complexation.…”

“…To overcome this barrier, new agents are continuously being developed that have better relaxation properties or a high payload of contrast materials. 3 For example, T 1 -based gadolinium (Gd) contrast agents have been heavily investigated due to their clinical translational values. Macromolecular carriers such as linear polymers 4 and dendrimers 5,6 can have hundreds or even thousands of Gd chelates covalently linked together, greatly enhancing the relaxation effects of these contrast agents on a per Gd basis.…”