The morphology of the cells cultured in the scaffolds was
observed by SEM. On day 14, the cells adhered to the scaffold were
washed once with phosphate buffered saline (PBS), and then fixed with Karnovsky’s fixative and osmium tetraoxide at 4 ◦C for 2 h.
After dehydration with graded alcohols, the cells were dried using
CO2. Each sample was gold sputtered in vacuum and examined by
SEM.