Figure 1

Morphological appearance of SF patches seeded with Ad-MSCs before and after decellularization. On SEM, untreated SF patches show their typical filamentous structure (A). In B and C, SF patches seeded with Ad-MSCs after two and seven days of culture, respectively. Note that at seven days the Ad-MSCs formed an almost uniform monolayer on SF patches (Scale bar 20 μm). This result was also seen on light microscopy after H&E staining (D); note that Ad-MSCs (arrows) have a spindle-shape morphology (asterisks indicate cell nuclei) (Scale bar 30 μm). After seven days of culture, Ad-MSCs-SF analyzed by confocal microscopy maintain the positive expression of mesenchymal markers CD146 (E) and CD44 (F) and of the integrin CD49d (G) and the negativity for the hematopoietic marker CD45 (H). Incubation of Ad-MSCs-SF with distilled H₂0 for one hour was effective in completely removing the cells from SF patches. H&E staining (I): no cellular elements remain attached on SF patches after decellularization; the pink spots (arrows) represent fibroin aggregates (Scale bar 20 μm). SEM (J): note the absence of cell debris (Scale bar 50 μm). In the figure: SF = silk fibroin; c = flattened Ad-MSCs. Ad-MSCs, adipose tissue derived mesenchymal stromal cells; SEM, scanning electron microscopy.