Fig. 3

Cryopreservation damage to other 3D mesenchymal stem cell (MSC) compositions, including cell sheets and spheroids. Cell sheets, cell spheroids, or clumps of mesenchymal stem cell/extracellular matrix complexes (C-MSCs) were generated and cryopreserved as described in the Methods. a Schematic figure of cell sheets and spheroids preparation and cryopreservation. (For C-MSC cryopreservation, see Fig. 1a.) Histological analysis of each cell construct before cryopreservation (b) or at 1 (c) and 5 days (e) after thawing. Serial sections were stained with hematoxylin and eosin (HE) and TUNEL as indicated. Scale bars = 200 μm. The percentage of TUNEL-positive apoptotic cells at 1 day (d) or 5 days (f) after thawing. Values represent means ± SD of four cultured cell constructs. Similar results were obtained from three independent experiments. **p < 0.01, by ANOVA with Tukey’s test. DAPI 4′,6-diamidino-2-phenylindole