US EPA

2708524 

Journal Article 

The detection of β-amyloid plaques in an Alzheimer's disease rat model with DDNP-SPIO 

Zhang, D; Fa, HB; Zhou, JT; Li, S; Diao, XW; Yin, W 

2015 

Yes 

Clinical Radiology
ISSN: 0009-9260
EISSN: 1365-229X 

70 

1 

74-80 

English 

25459675 

10.1016/j.crad.2014.09.019 

WOS:000347867300011 

http://://WOS:000347867300011
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AIM: To detect the β-amyloid plaques (Aβ) in a rat model of Alzheimer's disease (AD) using superparamagnetic iron oxide nanoparticles coated with 1,1-dicyano-2-[6-(dimethylamino)-naphthalene-2-yl] propene carboxyl derivative (DDNP-SPIO).

MATERIALS AND METHODS: DDNP-SPIO was prepared in a previous trial. The binding affinity of DDNP-SPIO to Aβ was tested using fluorescence spectrophotometry in vitro. In vivo, five AD rats and five non-AD rats were intravenously injected with DDNP-SPIO at a dose of 76 μmol Fe/kg. Coronal T2*-weighted images were collected at baseline and repeated at 10, 30, and 60 min post-injection. Enhancement features of the two groups were analysed. After imaging, brain specimens were resected for Congo red and Prussian blue staining to assess the binding of DDNP-SPIO to Aβ deposits.

RESULTS: In vitro experiments indicated that the DDNP-SPIO nanoparticles displayed high binding affinities towards Aβ with a Kd value of 29.4 nmol/l. A significant decrease in SI was detected in the hippocampal area of AD rats after intravenous injection of the nanoparticles, but not in non-AD rats. The measurement of the percentage signal loss decreased to 52% in AD rats. In non-AD rats, only 10% signal loss was observed. There was a significant difference between the two groups (t = 4.533, p < 0.05). The signal decrease resulted from the binding of the DDNP-SPIO nanoparticles to the Aβ plaques, which was identified with Congo red and Prussian blue staining.

CONCLUSION: The DDNP-SPIO nanoparticles could potentially be used for visualizing Aβ plaques, which may be helpful for diagnosing the early stages of AD and monitoring the effects of drug therapy.