Techniques for modifying the surface of implantable devices, such as bioprosthetic valves, to improve the biocompatibility of the implantable devices are provided. In particular, a customizable, non-fouling surface coating may be formed on the surface of implantable devices that improves the biocompatibility of the implantable devices and has the potential to further reduce the occurrence of complications for patients of all ages. Additionally, various molecules of interest to specifically promote endothelialization of the implantable device may be added to the surface coating, which may facilitate the formation of an endothelial layer on the surface of the implantable device that would naturally maintain a non-thrombogenic, non-immunogenic environment in the long-term.