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

Figure 6 Morphologies and cell viability of cellular co-spheroids. A: Fluorescent dye-labeled mesenchymal stem cells (MSCs) (PKH26, red), A549 (PKH67, green), or 3T3 (PKH67, green) cells were co-cultured on chitosan-hyaluronan (CS-HA) substrates for 3 d. The image of typical cell morphologies and vesicle-like bubbles on the cell membrane of the MSC/3T3 or MSC/A549 co-spheroids were taken by the inverted microscope; B: confocal images of co-spheroids co-cultured on CS-HA substrates for 2 d. The cell viability was detected by LIVE/DEAD staining with calcein AM (green) and ethidium homodimer-1 (red). Viable cells appear as green, while the red arrows indicate dead cells (red). Z-stack images were collected at 3 μm sections (total stacks approximately 25 images). BF: Bright field; MSC: Mesenchymal stem cells.