Enzymatic mediated poly (gallic acid) (PGAL), a stable multiradical polyanion with helicoidal secondary structure and high antioxidant capacity, was successfully grafted to poly(ε-caprolactone) (PCL) using UV-photo induction. PCL films were prepared with several levels of roughness and subsequently grafted with PGAL (PCL-g-PGAL). The results on the full characterization of the produced materials by mechanical tests, surface morphology, and topography, thermal and crystallographic analyses, as well as wettability and cell protection activity against oxidative stress, were adequate for tissue regeneration. The in vitro biocompatibility was then assessed with epithelial-like cells showing excellent adhesion and proliferation onto the PCL-g-PGAL films, most importantly, PCL-g-PGAL displayed a good ability to protect cell cultures on their surface against reactive oxygen species. These biomaterials can consequently be considered as novel biocompatible and antioxidant films with high-responsiveness for biomedical or tissue engineering applications.