Identification of Advanced Atherosclerotic Plaque in Abdominal Aorta in a Murine Atherosclerotic Model with 24p3 (Mouse Homologue of Neutrophil Gelatinase-Associated Lipocalin)-Targeted Micelles and MRI.

Bernard C. te Boekhorst¹, Sandra M. Bovens^1,2, Krista den Ouden¹, Marcel G. Nederhoff^1,2, Kees W. van de Kolk¹, Maarten J. Cramer¹, Michiel ten Hove¹, Pieter Doevendans¹, Robert E. Poelmann³, Gerard Pasterkamp¹, Cornelis J. van Echteld¹

Neutrophil gelatinase-associated lipocalin (NGAL) in human carotid artery plaque has been reported to correlate with the occurrence of acute cerebrovascular events. We calculated the normalized enhancement ratio (NER) of enhanced regions on T1 weighted MR images 72 hours after administration of both 24p3 (mouse homologue of NGAL) targeted and isotype-conjugated micelles (labeled with fluorophore and gadolinium). Maximal NER was respectively 2.25 and null. Fluorescence microscopy (FM) showed colocalization of abundantly present 24p3-targeted micelles and especially 24p3, and, only to a minor extent, macrophages. Isotype-conjugated micelles were only to a minor extent present in the plaque and colocalized only with macrophages.