Polyampholyte hydrogels have shown promise as functional biomaterial platforms with resistance to nonspecific protein adsorption (non-biofouling). Yet there are few zwitterionic cross-linkers available to complement these materials and provide an extended charge density throughout the 3D network. Recent development of a peptide-based zwitterionic cross-linker has shown merit. Indeed, the use of functionalizable amino acids allows for a series of peptide-based zwitterionic methacrylate and methacrylamide cross-linkers. Methacrylate additions prior to peptide coupling provides an “outside-in” strategy when using natural L-Serine or L-Lysine as substrates to produce a series of methacrylate and methacrylamide combinations and expand the library of peptide-based cross-linkers. Herein such dipeptide combinations include Ser-Lys; Lys-Ser and Lys-Lys zwitterionic bis(methacrylate/methacrylamide) cross-linkers. Highlighting the utility of the method, and potential to increase the distance between zwitterionic components, the syntheses of tripeptide Lys-Gly-Lys dimethacrylamide and Ser-Gly-Ser dimethacrylate are also shown.