Evaluation of atherosclerotic lesions using dextran- and mannan-dextran-coated USPIO: MRI analysis and pathological findings.

Abstract

Magnetic resonance imaging (MRI) can detect atherosclerotic lesions containing accumulations of ultrasmall superparamagnetic iron oxides (USPIO). Positing that improved USPIO with a higher affinity for atherosclerotic plaques would yield better plaque images, we performed MRI and histologic studies to compare the uptake of dextran- and mannan-dextran-coated USPIO (D-USPIO and DM-USPIO, respectively) by the atherosclerotic walls of rabbits. We intravenously injected atherosclerotic rabbits with DM-USPIO (n = 5) or D-USPIO (n = 5). Two rabbits were the controls. The doses delivered were 0.08 (dose 1) (n = 1), 0.4 (dose 2) (n = 1), or 0.8 (dose 3) (n = 3) mmol iron/Kg. The dose 3 rabbits underwent in vivo contrast-enhanced magnetic resonance angiography (MRA) before and 5 days after USPIO administration. Afterwards, all animals were euthanized, the aortae were removed and subjected to in vitro MRI study. The signal-to-noise ratio (SNR) of the aortic wall in the same region of interest (ROI) was calculated in both in vivo and in vitro studies. Histological assessment through measurement of iron-positive regions in Prussian blue-stained specimens showed that iron-positive regions were significantly larger in rabbits injected with DM- rather than D-USPIO (P < 0.05) for all doses. In vivo MRA showed that the SNR-reducing effect of DM- was greater than that of D-USPIO (P < 0.05). With in vitro MRI scans, SNR was significantly lower in rabbits treated with dose 2 of DM-USPIO compared with D-USPIO treatment (P < 0.05), and it tended to be lower at dose 3 (P < 0.1). In conclusion, we suggest that DM-USPIO is superior to D-USPIO for the study of atherosclerotic lesions in rabbits.

• Authors: Keiko Tsuchiya, Norihisa Nitta, Akinaga Sonoda, Ayumi Nitta-Seko, Shinichi Ohta, Masashi Takahashi, Kiyoshi Murata, Kenichi Mukaisho, Masashi Shiomi, Yasuhiko Tabata, Satoshi Nohara
• Journal: International journal of nanomedicine (Int J Nanomedicine) Vol. 7 Pg. 2271-80 ( 2012) ISSN: 1178-2013 [Electronic] New Zealand
• PMID: 22619561 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Coated Materials, Biocompatible
• Dextrans
• Magnetite Nanoparticles
• Mannans

Topics

• Animals
• Atherosclerosis (diagnosis, pathology)
• Cell Line
• Coated Materials, Biocompatible
• Dextrans
• Hyperlipoproteinemia Type II (pathology)
• Macrophages (physiology)
• Magnetic Resonance Angiography (methods, statistics & numerical data)
• Magnetite Nanoparticles
• Mannans
• Mice
• Nanomedicine
• Phagocytosis
• Rabbits
• Signal-To-Noise Ratio