Biopolymers such as proteins and nucleic acids are the key building blocks of life. Synthetic polymers have nevertheless revolutionized our everyday life through their robust synthetic accessibility. Combining the unmatched functionality of biopolymers with the robustness of tailorable synthetic polymers holds the promise to create materials that can be designed ad hoc for a wide array of applications. Radical polymerization is the most widely applied polymerization technique in both fundamental science and industrial polymer production. While this polymerization technique is robust and well controlled, it generally yields unfunctional all-carbon backbones. Combinations of natural polymers such as peptides, with synthetic polymers, are thus limited to tethering peptides onto the side chains or chain ends of the latter. This synthetic limitation is a critical restraint, considering that the function of biopolymers is programmed into the sequence of their main chain (i.e., primary structure). Here, we report the radical copolymerization of peptides and synthetic comonomers yielding synthetic polymers with defined peptide sequences embedded into their main chain. Key was the development of a solid-phase peptide synthesis (SPPS) approach to generate synthetic access to peptide conjugates containing allylic sulfides. Following cyclization, the obtained peptide monomers can be readily copolymerized with N,N-dimethylacrylamide (DMA)�controlled by reversible addition−fragmentation chain transfer (RAFT). Importantly, the developed synthetic strategy is compatible with all 20 standard amino acids and uses exclusively standard SPPS chemicals or chemicals accessible in one-step synthesis�prerequisite for widespread and universal application.

The development of sustainable plastic materials will be flanked with conscious resource management, waste recovery frameworks, and social change. Nonetheless, developing strategies toward controlled polymer degradation remains a key challenge—whether as a failsafe mechanism for materials that escape the resource recovery cycle, or where distinct degradation pathways are required for specific applications such as in the biomedical realm. This perspective highlights recent trends, challenges, and future strategies on three levels: 1) On the materials level, by the incorporation of enzymes into polymer materials that catalyze polymer degradation under benign conditions; 2) On the domain level, crystalline segments of polymer materials are often inert, even to enzymatically catalyzed degradation. Gaining an understanding of the mode of interaction between enzymes and polymer chains is key to controlling degradation of all polymer morphologies within materials. Processive depolymerization mechanisms, where the enzyme binds polymer chain ends and depolymerizes along the chain are extremely promising for efficient polymer degradation; 3) On the molecular level, where polyesters exhibit enzymatic targets of ester bonds through their polymer backbone, poly(alkene)s c of all carbon backbones. To enable degradation of this most abundant class of polymers, strategies must be developed to incorporate enzymatic targets into the backbone.

The folding of synthetic polymers into single chain nanoparticles draws inspiration from the folding of polypeptides into the functional macromolecular architectures of proteins. The building blocks of their natural inspiration,...