Fig. 1. Schematic of the fabrication and characterization of a N-FN patch.

a Fabrication of a polycaprolactone (PCL)-based FN patch. Inspired by the high aligned and well-organized nanotopography of the native ECM, the PCL-based FN patch was fabricated using capillary force lithography (CFL). Plasma surface modification on the surface of the FN patch. The surface of the patches was modified using N₂ plasma reaction gas. b SEM images of the surface of FN patches treated by N₂ plasma reaction gas under various times. Scale bars = 2 µm. c FT-IR analysis of the N-FF and N-FN patches treated plasma at various times. d XPS survey scans and e high-resolution N1s XPS spectra of FN patches and 30-min N-FN patches.