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The diagnostic value of iron oxide nanoparticles for imaging of myocardial inflammation--quo vadis?

Bietenbeck M, Florian A, Sechtem U, Yilmaz A - J Cardiovasc Magn Reson (2015)

Bottom Line: After intravenous administration, these nanoparticles are taken up by activated monocytes and macrophages, which predominantly accumulate in regions associated with inflammation as was successfully shown in recent preclinical studies.In this article, we outline the basic features of superparamagnetic iron oxide-based contrast agents and review recent studies using such nanoparticles for cardiac imaging in case of acute myocardial infarction as well as acute myocarditis.Moreover, we highlight the translational potential of these agents and possible research applications with regard to imaging and therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology and Angiology, Albert-Schweitzer-Campus 1, building A1, 48149, Münster, Germany.

ABSTRACT
Cardiovascular magnetic resonance (CMR) is an integral part in the diagnostic work-up of cardiac inflammatory diseases. In this context, superparamagnetic iron oxide-based contrast agents can provide additional diagnostic information regarding the assessment of myocardial infarction and myocarditis. After intravenous administration, these nanoparticles are taken up by activated monocytes and macrophages, which predominantly accumulate in regions associated with inflammation as was successfully shown in recent preclinical studies. Furthermore, first clinical studies with a new iron oxide-complex that was clinically approved for the treatment of iron deficiency anaemia recently demonstrated a superior diagnostic value of iron oxide nanoparticles compared to gadolinium-based compounds for imaging of myocardial inflammation in patients with acute myocardial infarction. In this article, we outline the basic features of superparamagnetic iron oxide-based contrast agents and review recent studies using such nanoparticles for cardiac imaging in case of acute myocardial infarction as well as acute myocarditis. Moreover, we highlight the translational potential of these agents and possible research applications with regard to imaging and therapy.

No MeSH data available.


Related in: MedlinePlus

Schematic drawing of a superparamagnetic iron oxide particle (left) comprised of the magnetic core and the polymeric shell. While the core represents the active substance of the contrast agent, the coating stabilizes the particle and can be used as a grafting platform for various functional groups. Such iron oxide particles are taken up by activated monocytes (right) that can be visualized by Prussian blue staining. Reproduced with permission from Boyer et al. [61] and Richards et al. [62]
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Fig2: Schematic drawing of a superparamagnetic iron oxide particle (left) comprised of the magnetic core and the polymeric shell. While the core represents the active substance of the contrast agent, the coating stabilizes the particle and can be used as a grafting platform for various functional groups. Such iron oxide particles are taken up by activated monocytes (right) that can be visualized by Prussian blue staining. Reproduced with permission from Boyer et al. [61] and Richards et al. [62]

Mentions: Nanoscaled particles with an iron oxide core and a polymer shell have been under investigation for the last two to three decades due to their versatile features. Probably most important, IONs exhibit superparamagnetic properties below a certain particle size. As a result, they show a much larger magnetic susceptibility than paramagnetic agents. However, they lose their magnetization in the absence of an applied magnetic field – in contrast to paramagnetic agents. An attractive feature of IONs is that, depending on their size and composition of their polymer shell, they are biocompatible and may form stable colloidal suspensions, which are equally important prerequisites for successful in vivo applications (Fig. 2). After intravenous administration, IONs disperse freely in the intravascular blood pool – until they are eventually internalized by monocytes/macrophages of the reticuloendothelial system (RES) [14]. Therefore, IONs have mainly been used for blood-pool imaging or examinations of organs associated to RES such as liver, spleen and lymph nodes. However, in the presence of an inflammatory disease, IONs are avidly taken up by activated monocytes/macrophages with subsequent accumulation in the affected organ/tissue [15]. In addition, free IONs may migrate passively across leaky endothelium at inflammatory foci and get phagocytosed by resident tissue macrophages [12]. Thus – despite remaining predominantly intravascular – IONs represent promising tracers for inflammation. Exploiting this feature and their superior magnetic properties, tracking and visualization of internalized IONs by appropriate CMR sequences have great potential in the assessment of inflammatory processes. Moreover, appropriate surface modifications can functionalize IONs for several applications besides imaging. Amongst many others, their use in targeted drug delivery, magnetofection, hyperthermia or ex vivo molecular diagnostics have been reported [16].Fig. 2


The diagnostic value of iron oxide nanoparticles for imaging of myocardial inflammation--quo vadis?

Bietenbeck M, Florian A, Sechtem U, Yilmaz A - J Cardiovasc Magn Reson (2015)

Schematic drawing of a superparamagnetic iron oxide particle (left) comprised of the magnetic core and the polymeric shell. While the core represents the active substance of the contrast agent, the coating stabilizes the particle and can be used as a grafting platform for various functional groups. Such iron oxide particles are taken up by activated monocytes (right) that can be visualized by Prussian blue staining. Reproduced with permission from Boyer et al. [61] and Richards et al. [62]
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4495803&req=5

Fig2: Schematic drawing of a superparamagnetic iron oxide particle (left) comprised of the magnetic core and the polymeric shell. While the core represents the active substance of the contrast agent, the coating stabilizes the particle and can be used as a grafting platform for various functional groups. Such iron oxide particles are taken up by activated monocytes (right) that can be visualized by Prussian blue staining. Reproduced with permission from Boyer et al. [61] and Richards et al. [62]
Mentions: Nanoscaled particles with an iron oxide core and a polymer shell have been under investigation for the last two to three decades due to their versatile features. Probably most important, IONs exhibit superparamagnetic properties below a certain particle size. As a result, they show a much larger magnetic susceptibility than paramagnetic agents. However, they lose their magnetization in the absence of an applied magnetic field – in contrast to paramagnetic agents. An attractive feature of IONs is that, depending on their size and composition of their polymer shell, they are biocompatible and may form stable colloidal suspensions, which are equally important prerequisites for successful in vivo applications (Fig. 2). After intravenous administration, IONs disperse freely in the intravascular blood pool – until they are eventually internalized by monocytes/macrophages of the reticuloendothelial system (RES) [14]. Therefore, IONs have mainly been used for blood-pool imaging or examinations of organs associated to RES such as liver, spleen and lymph nodes. However, in the presence of an inflammatory disease, IONs are avidly taken up by activated monocytes/macrophages with subsequent accumulation in the affected organ/tissue [15]. In addition, free IONs may migrate passively across leaky endothelium at inflammatory foci and get phagocytosed by resident tissue macrophages [12]. Thus – despite remaining predominantly intravascular – IONs represent promising tracers for inflammation. Exploiting this feature and their superior magnetic properties, tracking and visualization of internalized IONs by appropriate CMR sequences have great potential in the assessment of inflammatory processes. Moreover, appropriate surface modifications can functionalize IONs for several applications besides imaging. Amongst many others, their use in targeted drug delivery, magnetofection, hyperthermia or ex vivo molecular diagnostics have been reported [16].Fig. 2

Bottom Line: After intravenous administration, these nanoparticles are taken up by activated monocytes and macrophages, which predominantly accumulate in regions associated with inflammation as was successfully shown in recent preclinical studies.In this article, we outline the basic features of superparamagnetic iron oxide-based contrast agents and review recent studies using such nanoparticles for cardiac imaging in case of acute myocardial infarction as well as acute myocarditis.Moreover, we highlight the translational potential of these agents and possible research applications with regard to imaging and therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology and Angiology, Albert-Schweitzer-Campus 1, building A1, 48149, Münster, Germany.

ABSTRACT
Cardiovascular magnetic resonance (CMR) is an integral part in the diagnostic work-up of cardiac inflammatory diseases. In this context, superparamagnetic iron oxide-based contrast agents can provide additional diagnostic information regarding the assessment of myocardial infarction and myocarditis. After intravenous administration, these nanoparticles are taken up by activated monocytes and macrophages, which predominantly accumulate in regions associated with inflammation as was successfully shown in recent preclinical studies. Furthermore, first clinical studies with a new iron oxide-complex that was clinically approved for the treatment of iron deficiency anaemia recently demonstrated a superior diagnostic value of iron oxide nanoparticles compared to gadolinium-based compounds for imaging of myocardial inflammation in patients with acute myocardial infarction. In this article, we outline the basic features of superparamagnetic iron oxide-based contrast agents and review recent studies using such nanoparticles for cardiac imaging in case of acute myocardial infarction as well as acute myocarditis. Moreover, we highlight the translational potential of these agents and possible research applications with regard to imaging and therapy.

No MeSH data available.


Related in: MedlinePlus