Electrospun Collagen: A Tissue Engineering Scaffold with Unique Functional Properties in a Wide Variety of Applications

Figure 1

Endothelial interactions with electrospun collagen ((a)–(h)) and gelatin ((i)–(p)). Endothelial cell shape varied as a function of increasing fiber diameter on both electrospun collagen (Day 1: (a), (c), (e), (g) & Day 7: (b), (d), (f), (h)) and electrospun gelatin (Day 1: (i), (k), (m), (o) & Day 7: (j), (l), (n), (p)). Cell shape established during the early stages of plating persisted throughout the entire culture interval (e.g., for each scaffold cells at day 1 appeared to exhibit a similar cell shape after 7 days of culture). Cells expressed and retained a highly flattened and stellate shape when plated onto scaffolds composed of fibers less than 1,500 nm ((a)–(l)). At larger fiber sizes the cells exhibited a more elongated phenotype, this was especially evident on the collagen-based scaffolds ((e), (f), (g) and (h)). Penetration into the scaffolds was primarily regulated by average fiber diameter and pore size. TEMs of cross-sectional images of cells plated onto electrospun collagen ((q)–(t)) and electrospun gelatin ((u)–(x)) for 10 days. Average fiber diameters for collagen (a) & (q) = 449 ± 122 nm, (c) & (r) = 1,187 ± 297 nm, (e) & (s) = 1,886 ± 513 nm and (g) & (t) = 2,756 ± 855 nm. In gelatin (i) & (u) = 198 ± 50 nm, (k) & (v) = 491 ± 114 nm, (m) & (w) = 1,252 ± 302 nm, and (o) & (x) = 1,619 ± 414 nm (all fiber measurements from dry scaffolds prior to processing for cross-linking). Note that penetration was not evident until a nominal average fiber diameter of about 1,800 nm was achieved in the scaffolds (arrows in (r), (t), (x) indicate fibers in cross section). Scale bar in (a) = 20 μm.