Micropatterned poly(d,l-lactide-co-caprolactone) films entrapped with gelatin for promoting the alignment and directional migration of Schwann cells

Abstract

Engineering microstructures with bioactive molecules critically influences Schwann cell (SC) behaviors in terms of cellular spatial arrangement and directional migration, which are advantageous for expediting the repair of peripheral nerve defects. In this study, stripe micropatterns were fabricated on poly(D,L-lactide-co-caprolactone) (PLCL) films by thermo-pressing using polydimethylsiloxane (PDMS) stamps with ridges/grooves of 3/3 and 10/10 μm in width. Their surfaces were further entrapped with 0.7 μg cm⁻² and 1.9 μg cm⁻² gelatin by a facile swelling–shrinking entrapment technique using lower and higher concentrations of gelatin solutions, respectively. The surfaces entrapped with gelatin became more hydrophilic. On the micropatterned surfaces, the water droplet had an ellipse shape and exhibited an orientation along the stripes. The gelatin-entrapped and micropatterned PLCL surfaces could guide the adhered SCs to form an elongated shape with a higher length to width ratio along the stripes. The migration rate of the SCs was significantly enhanced parallel to the stripe direction, and was fastest on the 3/3 μm PLCL films entrapped with 1.9 μg cm⁻² gelatin. The vinculin expression, adhesion force and expression of adhesion and migration-related genes such as integrin β1, Rac1, RhoA and Cdc42 revealed a stronger affinity of the SCs to the 3/3 μm PLCL films with a higher gelatin density.