National Research Council of Canada. Human Health Therapeutics
cell adhesion; cell; cytology; diagnosis; dissociation; endothelial cells; infrared devices; mammals; molecules; neurodegenerative diseases; pathology; Alzheimer's disease; aptamers; near-infrared fluorescence imaging; therapeutic monitoring; vascular cell adhesion; vcam-1; molecular imaging; amyloid beta protein; aptamer; cyanine dye 5 11R6; fluorescein; fluorescent dye; single stranded DNA; vascular cell adhesion molecule 1; animal experiment; animal model; animal tissue; cerebellum; DNA library; DNA sequence; electrophoretic mobility; fluorescence imaging; fluorescence microscopy; gel mobility shift assay; human cell; in vitro selection; In vivo study; mouse; nervous system inflammation; protein targeting; umbilical vein endothelial cell; disease model; fluorescence imaging; genetics; inflammation; metabolism; molecular imaging; nucleotide sequence; transgenic mouse; aptamers, nucleotide; base sequence; disease models, animal; human umbilical vein endothelial cells; inflammation; mice, transgenic; optical imaging
Cerebrovascular inflammation is often involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). Non-invasive and sensitive molecular imaging of cerebrovascular inflammation biomarkers therefore represents a potential AD diagnostic and therapeutic monitoring method. Here, we describe the development of a novel aptamer-based near infrared fluorescence imaging probe targeting Vascular Cell Adhesion Molecule-1 (VCAM-1), an adhesion molecule overexpressed by the activated cerebrovasculature during inflammation. A SELEX-type screening of a random ssDNA library against human VCAM-1 identified a high-affinity ssDNA aptamer with a dissociation constant of 49 nM. We demonstrated that the Cy5.5-labeled aptamer binds to activated endothelial cells, with no affinity to nonactivated cells. A scrambled aptamer labeled with Cy5.5 did not image activated and non-activated endothelial cells, confirming the sequence specificity of the targeting. In vivo, the aptameric imaging agent targeting VCAM-1 successfully identified inflammation associated with amyloid-β plaques deposition in the vessels of the cerebellum of transgenic AD mice. It exhibited excellent retention by remaining bound to vessels 4 hours post-injection, indicating its effectiveness in in vivo imaging and its potential in early detection of cerebrovascular inflammation.
Journal of Biomedical Nanotechnology11, no. 12 (December 2015): 2264–2274.