Validation Study of MRI Contrast Agent of Gd-DOTA Conjugated to DNA Aptamer for Detecting Oligomeric Amyloid-beta

The oligomeric amyloid-b (oAβ) is a reliable feature for an early diagnosis of Alzheimer's disease (AD). Therefore, the objective of this study was to demonstrate imaging of oAβ deposits using our developed DNA aptamer called ob5 conjugated with gadolinium (Gd)- DOTA as a contrast agent for early diagnosis of AD using MRI. An oAβ-specific aptamer was developed by amide bond formation and conjugated to Gd-DOTA MRI contrast agent and/or cyanine5 (cy5). We verified the performance of our new contrast agent with AD model mice using In vivo and ex vivo fluorescent imaging and animal MRI experiments.