Fig. 1
Morphological evaluation of MSCs cultivated with biomaterials. a–d Scanning electron microscopy (SEM) of equine adipose-derived mesenchymal stem cells (N = 8) cultivated in growth medium in conjunction with MC and B30 biomaterials for 48 h. a, b SEM of native CultiSpher-S MC and B30 biomaterials without MSCs. c, d SEM of combined cultivation of MSCs together with MC and B30 show cell adhesion, aggregation, and intercellular contacts. e, f Phase contrast (PC) images of MSCs seeded in a monolayer or in combination with MC. g, h Histological paraffin section of the MSCs pellet in conjunction with MC stained with H&E shows cell migration (black arrow) within the pores of the MC. i–l Combined cultivation of MSCs in conjunction with B30 (i, j) and MC (k, l) after static (SC) and mechanical rotation (RT) culture for 72 h show the pattern of cell adhesion and detachment from the pellet using phalloidin staining (green). Hoechst counterstain visualizes cell nuclei (blue). m TEM of combined MSCs and B30 biomaterial section show the phagocytic properties of MSCs to the biomaterials using podocytes extension (star). n TEM of MSCs section demonstrates various sized of B30 granules within the cell cytoplasm (black arrow). o Combined cultivation of MSCs with MC and B30 biomaterials under both SC and mechanical rotation culture (RC). Average quantification of cell viability using a microplate reader at 570 nm. Enhanced cell viability in the presence of MC compared to B30 can be shown. Cells cultivated in basal medium (BM) without any biomaterials were used as a negative control. p Average CSA measurement (μm2) for combined MSCs and biomaterial pellet up to 72 h (h, N = 4). q Linear correlation between the cultivation time point and the size of the MSCs and biomaterials (BMS, N = 4). All data presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001. Scale bar in a, b = 200 nm, c, d = 2000 nm, e, f = 100 μm, g, h = 70 μm, i–l =20 μm, and m, n = 2500 nm