Here, We report a method for synthesis of cylindrical copolypeptide brushes via N-carboxyanhydride (NCA) polymerization utilizing a new tandem catalysis approach that allows preparation of brushes with Controlled segment lengths in a straightforward, one-pot procedure. requiring no intermediate isolation or purification steps. To obtain high-density brush copolypeptides, we used a "grafting from approach where alloc-alpha-aminoamide groups were installed onto the side chains of NCAs to serve as masked initiators. These groups were inert during cobalt initiated NCA polymerization and gave allyloxycarbonyl-alpha-aminoamide-substituted Polypeptide main chains. The alloc-alpha-aminoamide groups were then activated in situ using nickel to generate initiators for growth of side-chain brush segments. This use of stepwise tandem cobalt and nickel catalysis was found to be an efficient method for preparation of high-chain-density, cylindrical copolypeptide brushes, where both the main chains and side chains can be prepared with controlled segment lengths