A research team led by Professor Joo H. Kang in the Department of Biomedical Engineering at UNIST has reported a hemolysis-free and highly efficient blood plasma separation platform. In their study, the research team used diamagnetic repulsion of blood cells to separate blood cells and blood plasma. Once super paramagnetic iron oxide nanoparticles (SPIONs) are supplemented to whole blood, the SPIONs turn the blood plasma into a paramagnetic condition, and thus, all blood cells are repelled by magnets. The research team collected hemolysis-free plasma without loss of plasma proteins, platelets, and exosomes.
(A) A schematic illustration of the microfluidic device for blood plasma separation using diamagnetic repulsion of blood cells. (B) An image showing red blood cells diamagnetically repelled by permanent magnets.
”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,” says Professor Kang.
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.
“We have overcome the limitations of a filter-based blood plasma separation method that potentially could induce hemolysis or a microfluidic chip-based plasma separation method that has the problems in a plasma recovery rate and purity,” says Research Professor Seyong Kwon in the Department of Biomedical Engineering at UNIST, the first co-author of the study.
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,” says Jieung Oh, the first co-author of the study.
A schematic drawing of the microfluidic device for centrifugation-free immunoassay and the results of the immunoassay
Min Seok Lee of the Department of Biomedical Engineering at UNIST also participated in this study. This work was studied in collaboration with Professor Joonwoo Jeong and Research Professor Eujin Um in the Department of Physics at UNIST. The findings of this research have been published in the online version of Small on May 12th, 2021 and selected as a back cover image. This work was supported by Samsung Research Funding Center for Future Research, the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education.
