Changes of cell membrane fluidity for mesenchymal stem cell spheroids on biomaterial surfaces

Figure 7 Membrane fluidity of cells for co-cultured cellular spheroids on tissue culture polystyrene or chitosan-hyaluronan substrates. Membrane fluidity was determined by translocation of the membrane labeling fluorescent dyes. A: Illustration of experimental procedures for the determination of membrane fluidity. Fluorescent dye-labeled mesenchymal stem cells (MSCs) (PKH26, red), A549 (PKH67, green), or 3T3 (PKH67, green) cells were cultured on tissue culture polystyrene (TCPS) or chitosan-hyaluronan (CS-HA) substrates for 3 d. Then, the cells on TCPS were detached by trypsin and the co-spheroids on CS-HA were dissociated by Accumax. The single cell suspension was subjected to imaging and flow cytometry analysis to obtain the respective ratios of cells labeled with single and double fluorescent dyes; B: Respective ratios of the cells labeled with single and double fluorescent dyes determined by flow cytometry; C: The confocal image of single cells dissociated from MSC/A549 or MSC/3T3 co-spheroids by Accumax. Scale bar: 50 μm. TCPS: Tissue culture polystyrene; CS-HA: Chitosan-hyaluronan; MSC: Mesenchymal stem cells.