Radiolabeled Fucoidan as a P-Selectin Targeting Agent for In Vivo Imaging of Platelet-Rich Thrombus and Endothelial Activation

Aortic valve endocarditis in rat. Coronal and sagittal slices on SPECT/CT coregistration are shown, with an example of focal ^99mTc-fucoidan uptake (red cross) in aortic valve area. Additional uptake is seen in spine and upper extremities of humeral bones.

Aortic valve endocarditis in rat. Comparison of histology (5-μm thickness, Alcian blue staining), autoradiography, and P-selectin immunostaining (with nuclear counterstaining) in same vegetation (adjacent slices for histology and autoradiography but not for immunostaining). Two vegetations are present on this sample: one attached to aorta wall damaged by catheter path (solid arrow) and second attached to aortic valve (dotted arrow). There is clear colocalization of ^99mTc-fucoidan uptake and immunostaining on both vegetations but not within damaged myocardium underlying vegetation (proteoglycans are stained in blue, indicated by arrowheads).

Intraluminal thrombus in AAA in rat. Compared analysis of histology (Masson trichrome) and autoradiography on same slice (cryostat section, 20-μm thickness; Masson trichrome staining has been performed after autoradiographic acquisition) and P-selectin immunostaining with nuclear counterstaining (different sample). Mural thrombus on Masson trichrome staining (arrows) matched ^99mTc-fucoidan uptake on autoradiography. P-selectin positivity on immunostaining was localized within thrombus, which is spreading at surface of aneurysm wall.