title: Enrichment of live unlabelled cardiomyocytes from heterogeneous cell populations using manipulation of cell settling velocity by magnetic field.
abstract: The majority of available cardiomyocyte markers are intercellular proteins, limiting our ability to enrich live cardiomyocytes from heterogeneous cell preparations in the absence of genetic labeling. Here, we describe enrichment of live cardiomyocytes from the hearts of adult mice in a label-free microfluidic approach. The separation device consisted of a vertical column (15 mm long, 700 μm diameter), placed between permanent magnets resulting in a field strength of 1.23 T. To concentrate the field at the column wall, the column was wrapped with 69 μm diameter nickel wire. Before passing the cells through the column, the cardiomyocytes in the cell suspension had been rendered paramagnetic by treatment of the adult mouse heart cell preparation with sodium nitrite (2.5 mM) for 20 min on ice. The cell suspension was loaded into the vertical column from the top and upon settling, the non-myocytes were removed by the upward flow from the column. The cardiomyocytes were then collected from the column by applying a higher flow rate (144 μl/min). We found that by applying a separation flow rate of 4.2 μl/min in the first step, we can enrich live adult cardiomyocytes to 93% ± 2% in a label-free manner. The cardiomyocytes maintained viability immediately after separation and upon 24 h in culture.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Aarash
authors.initials: A
authors.lastname: Sofla
authors.affiliation: University of Kragujevac, Kragujevac, Serbia.
authors.forename: Bojana
authors.initials: B
authors.lastname: Cirkovic
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Hsieh
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Miklas
authors.affiliation: University of Kragujevac, Kragujevac, Serbia.
authors.forename: Nenad
authors.initials: N
authors.lastname: Filipovic
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada ; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.
authors.forename: Milica
authors.initials: M
authors.lastname: Radisic