Fig. 3

Ultrastructural characteristics of rat SMG tissue and SMG-ECM-treated aggregates were remarkably similar. a Transmission electron micrographs of rat SMG (positive control tissue) thin sections. Scale bar is shown in each panel. N: cell nucleus; SG: secretory granule (note the presence of two types of granules, electron dense and less electron dense); TJ: tight junction (identified with thin arrow pointers). b Transmission electron micrographs of cell aggregates that formed when BM-MSCs were incubated with SMG-ECM for 1 h and then cultured for 14 days. Note the presence of structures (e.g., electron dense secretory granules; formation of tight junctions; location of the nucleus near the cell membrane) found in rat SMG tissue that can also be seen in the cell aggregates. Scale bar is shown in each panel. c Transmission electron micrographs of BM-MSCs that formed a monolayer after treatment with SMG-ECM and culture for 14 days (Mono/SMG-ECM) and untreated BM-MSCs. Scale bar is shown in each panel. Images were selected from original work published by BioMed Central in Tran et al.²²¹