Nanofibrous modification on ultra-thin poly(e-caprolactone) membrane via electrospinning

Poly(e-caprolactone) (PCL) is a favorable material for tissue engineering. PCL was successfully fabricated into less than 10 μm thin membranes using a 2-roll-heated-mill and biaxial stretching process. However, PCL is known for its poor cellular adhesion and surface modifications are needed for any tissue engineering applications. This paper reports on a novel surface modification technique of the PCL membrane by coating with electrospun nanofibers. The purpose was to mimic the architecture of the natural extracellular matrix and create nanotopography for enhanced cellular attachment. The surfaces were characterized by scanning electron microscopy (SEM), water contact angle and atomic force microscopy. The results showed that uniform nanofibrous topology were successfully achieved on the surface of the PCL membrane, with increased roughness (more than 17 times) and surface area. This nanofibrous topology induced capillary effects after sodium hydroxide (NaOH) treatment, causing the water contact angle to drop to almost zero. Scratch tests revealed a strong interaction of PCL nanofiber coating on the PCL membrane. AlamarBlue assay indicated that 3T3 fibroblast cells proliferated well on the nanofibrous membrane. Confocal Laser Scanning Microscope revealed better cell attachment onto the nanofibrous membranes than the untreated membranes. Results from SEM showed that the cells' spindle-shaped morphology on the NaOH-treated fibrous surface was evident while they remained in isolated spherical shaped entities in the non-treated fibrous surfaces.