Encapsulation of Superparamagnetic Nanoparticles Into Red Blood Cells as New Carriers of MRI Contrast Agents

Abstract

Aims: The half-life of superparamagnetic iron oxide nanoparticles in the bloodstream is very short since they are rapidly taken up by the reticuloendothelial system. In this article, we report the encapsulation of different magnetic nanoparticles into human erythrocytes to increase their blood circulation time. Materials & methods: Newly synthesized and commercially available nanoparticles were evaluated for the encapsulation into red blood cells through the transient opening of membrane pores by controlled hypotonic dialysis and successive isotonic resealing and reannealing of cells. Results: Commercial superparamagnetic iron oxide nanoparticles (SHU 555A, AMI 227 and PMP-50) dextran or carboxydextran coated can be successfully loaded into red blood cells; similarly, some of the new nanomaterials, such as Np-1 nanoparticles dispersed in the Disperbyk^®-190 agent, can be efficiently encapsulated into red blood cells. Conclusion: A careful consideration of magnetic nanoparticles parameters, such as size, synthesis protocols, coating and/or dispersant agents, is required in order to obtain efficient loading through the cell membrane pores.

Keywords::

• coating
• iron oxide superparamagnetic nanoparticles
• MRI contrast agents
• red blood cells
• reticuloendothelial system

Financial & competing interests disclosure

This work was supported by the European Commission and the Integrated Project NACBO (contract number NMP4-CT-2004-500804-2). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This work was supported by the European Commission and the Integrated Project NACBO (contract number NMP4-CT-2004-500804-2). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.