SAIO is expected to play a vital role in increasing the accuracy of the diagnosis of cerebro-cardiovascular diseases such as stroke, myocardial infarction, angina, and dementia. It was also found that SAIO was stable without aggregation nor iron leaching for up to a year.ĭirector Cheon said, "SAIO is a next-generation contrast agent that satisfies both high resolution and safety at the same time." SAIO has an excellent renal clearance profile without accumulation in liver or spleen. In addition to having high resolution, excretion of the contrasting agent through urine is especially important to avoid its accumulation within the body, which can cause various side effects. These excellent properties of the SAIO allowed the researchers to observe the heart blood vessels, which are hardly visible with current MRI contrast agents. In addition, to excellent resolution, the enhancement lasts substantially longer (>10 min) in comparison to Dotarem (< 2 min), which gives the radiologist an ample amount of time to carry out the imaging procedures. It has achieved a 3D brain vascular mapping that can clearly identify brain microvessels as thin as a hair (100 microns) in animal experiments. SAIO is one of the highest resolution imaging agents, which is 10 times more precise than the image generated using current contrast agents. Evaluating the Seven Components of Wisdom.Using AI to Achieve Earlier Diagnosis of Pancreatic Cancer.The researchers compared the contrast performance, retention, and renal clearance profile of the SAIO against Dotarem (a gadolinium-based agent) and iron oxide nanoparticles. The hybrid nature of the SAIOs gives them both excellent biocompatibility and imaging performance. This core is then coated with an iron oxide surface to give it paramagnetic properties at room temperature. The SAIO is a special nanoparticle that consist of a polysaccharide core made primarily with dextran cross-linked with other molecules. This allows it to circulate across blood vessels in the body.
The particle is 5 nanometers in size, which is about 1,500 times smaller than the microvascular diameter. The researchers developed a nanoparticle-based MRI contrast agent, called SAIO (Supramolecular Amorphous-like Iron Oxide). There have been some attempts to use paramagnetic iron-based nanoparticles as contrasting agents, but their renal clearance profile must be improved to prevent undesirable accumulation in the liver and other organs.Ī collaborative research team led by Professor Cheon Jinwoo, the director of the Center for Nanomedicine (CNM), Institute for Basic Science (IBS) at Yonsei University, Seoul, South Korea and Professor CHOI Byoung Wook from Yonsei University College of Medicine developed a high-performance MRI contrast agent for 3D vascular mapping. However, even then there are some health risks of nephrogenic systemic fibrosis for patients with poor kidney functions.
Free gadolinium ions have high toxicity, and thus they must be administered in chelated forms. Commonly used products are the gadolinium-based contrast agents. Just as satellites or global positioning systems (GPS) give traffic congestion information, the MRI contrast agents can give accurate information of vascular conditions such as vascular blockage and stenosis. In MRI, contrast agents improve the visibility of the structures such as smaller blood vessels within the body. For this purpose, imaging techniques such as magnetic resonance imaging (MRI) are widely used to identify the narrowing or blockage of blood vessels. Superparamagnetic iron oxide (SPIO) particles can be detected at micromolar concentrations of iron, and offer sufficient sensitivity for T2 ()-weighted imaging. As the disease often results in sudden death with few special prognostic symptoms, early diagnosis is very important. In order to provide a different signal intensity of the target, gadolinium-based MR contrast agents can be employed although they suffer from an inherent high threshold of detectability. Heart attack and stroke are the first and second leading causes of death in developed countries, respectively. In this review, we focus on the ES-MIONs because ES-MIONs avoid the disadvantages of MION-based T 2- and gadolinium chelate-based T 1-weighted contrast agents.Ĭontrast agents extremely small MIONs (ES-MIONs) magnetic iron oxide nanoparticles (MIONs) magnetic resonance imaging (MRI) synthesis methods.Reviewed by Emily Henderson, B.Sc. In addition, the MIONs larger than 10 nm can be used as negative contrast agents and the recently emerged extremely small MIONs (ES-MIONs) smaller than 5 nm are potential positive contrast agents.
Herein, we only focus on the liquid-based synthesis methods including aqueous phase methods and organic phase methods. Currently, many methods have been reported for the synthesis of MIONs. This review article introduces the methods of synthesizing MIONs, and their application as MRI contrast agents. Magnetic iron oxide nanoparticles (MIONs) have attracted enormous attention due to their wide applications, including for magnetic separation, for magnetic hyperthermia, and as contrast agents for magnetic resonance imaging (MRI).