Block macromonomers, comprising of a hydrophobic PLA biodegradable core and hydrophilic PEG ends, were enhanced to include photopolymerizable reactive groups to allow the macromonomers to form highly cross-linked, mechanically stable biopolymers. These newly synthesized cross-linked biomaterials with a reverse block structure from traditional PLA–PEG–PLA macromonomers were characterized in this study in an effort to expand their potential use in applications such as drug delivery vehicles,