Advancing highly tunable synthetic materials to operate in an increasingly cooperative fashion with biological systems and the environment provides a compelling opportunity to expand the repertoire and enhance the performance of critically needed technologies. To this end, we are developing new building blocks for polymer biomaterials so as to access to a breadth of thermomechanical properties and promote productive interactions with biological systems. The first part of this talk will describe our research on mirror image peptide complexes, or ‘stereocomplexes’, as tunable, transient junctions in synthetic polymer biomaterials. Varying the primary structure of the peptides and solvent conditions were found to markedly impact the secondary structure, which in turn determined the macroscale properties of polymer-peptide conjugates. These junctions are envisioned as molecular ‘VELCRO®’ strips and are anticipated to impart a myriad of adaptive properties, including self-healing and shear thinning, useful for 3D printing-based manufacturing processes and targeting biological proteins, among other applications. Another approach to engineer adaptive materials involves controlling degradation rates, and the second part of this talk will describe the synthesis, thermomechanical characterization, and degradation profiles of poly(β-amino ester) networks. By adjusting monomer composition, networks were obtained with degradation times scales that spanned hours to months. Synthetically accessible and highly tunable, this polymer platform offers enormous opportunities, from sacrificial template materials for biomanufacturing to commodity materials that degrade after their useful lifetime. Ultimately, by intertwining concepts from small molecule and peptide chemistry with polymer science and engineering, we aim to advance polymer and peptide building blocks, and thereby contribute to next generation materials and technologies for healthcare and beyond.