Esophageal epithelium regeneration on fibronectin grafted poly(L-lactide-co-caprolactone) (PLLC) nanofiber scaffold

In order to mimic normal epithelium regeneration on synthetic scaffold in vitro, biodegradable elastic poly(l-lactide-co-caprolactone) (PLLC) was processed into nanofibrous scaffold using electrospinning technology. An adhesive protein, fibronectin (Fn), was grafted onto the scaffold fiber surface via a two-step reaction: polyester aminolysis followed by Fn coupling via glutaraldehyde. Tensile testing was performed to measure the effect of aminolysis on the scaffold mechanical properties. The strain decreased but the tensile strength remained almost constant after aminolysis. However, no obvious difference of the nanofiber surface morphology was found after Fn grafting using scanning electron microscopy (SEM). Porcine esophageal epithelial cells were seeded on the Fn bonded scaffold to test the cell growth promotion against the control unmodified PLLC nanofiber scaffold using tissue culture polystyrene (TCPS) plate as a reference. Anti-cytokeratin AE1/AE3 was used as the primary antibody to confirm the esophageal epithelial phenotype. SEM observation, immunostaining and Western Blotting to compare the collagen type IV synthesis showed that the Fn grafted on PLLC scaffold greatly promotes epithelium regeneration. This modified scaffold is expected to be a good candidate for functional esophagus substitutes.