In their study, the research team used diamagnetic repulsion of blood cells to separate blood cells and blood plasma. Once superparamagnetic iron oxide nanoparticles (SPIONs) are supplemented to whole blood, the SPIONs turn the blood plasma into a paramagnetic condition, and thus, all blood cellsare repelled by magnets. The research team collected hemolysis-free plasma without loss of plasma proteins, platelets, and exosomes.
Many efforts have been made to develop various blood plasma separation methods. However, there always have been limitations, such as dilution of blood, blood cell impurity in plasma, and hemolysis. Our approach overcame these unmet challenges and we could provide a huge impact on in vitro diagnosis once this platform is translated into a commercial point-of-care device.
The developed blood plasma separation method achieved 100% of the plasma purity and 83.3% of the plasma volume recovery rate without noticeable hemolysis or loss of proteins in blood plasma, which was elusive with the conventional plasma separation devices. Moreover, this method enabled the greater recovery of bacterial DNA from the infected blood than centrifugation and immunoassays in whole blood without prior plasma separation.
Fig: Clinical applications of the diamagnetic plasma separation method for biomarker detection.
The developed blood plasma separation method also allowed them to collect platelet rich plasma (PRP). This capability is important because recent studies have revealed that platelets could be used as a biomarker for diagnosis of cancer or diabetes. Unlike a complex process of the conventional centrifugation method to collect PRP, our method can simply collect PRP by just tuning flow rates.
Seyong Kwon et al, Enhanced Diamagnetic Repulsion of Blood Cells Enables Versatile Plasma Separation for Biomarker Analysis in Blood, Small (2021). DOI: 10.1002/smll.202100797