In the field of tissue engineering many different materials have been investigated as supporting scaffolds. Electrospun nanofibers prepared from polycaprolactone (PCL) exhibit promising properties, but require further processing to improve its poor wettability. Dielectric barrier discharge (DBD) is a method of choice for a low cost, upscalability and environmental friendliness. Plasma polymer thin film containing carboxyl groups significantly lowers water contact angle of PCL nanofibers. We have investigated the plasma co-polymerization of maleic anhydride and acetylene in the DBD. Thin films containing anhydride and carboxyl groups were deposited on PCL electrospun nanofibers and Si substrates. The surface chemistry and the morphology of the samples were studied by analytical techniques including Fourier transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). In adjusted condition the film exhibited up to 11 at.% of carboxyl groups, while being relatively stable in water. Treatment also led to improved wettability of nanofibers, as the WCA decreased from 115 +/- 2 degrees to 0 degrees.