De Novo Amyloid Peptide-Polymer Blends with Enhanced Mechanical and Biological Properties

Amyloid peptides are structurally diverse materials that exhibit different properties depending on their self-assembly. While they are often associated with neurodegenerative diseases, functional amyloids play important roles in nature and exhibit properties with high relevance for biomedical applications, including remarkable strength, mechanical stability, antimicrobial and antioxidant properties, low cytotoxicity, and adhesion to biotic and abiotic surfaces. Challenges in developing amyloid biomaterials include the complexity of peptide chemistry and the practical techniques required for processing amyloids into bulk materials. In this work, two de novo decapeptides with fibrillar and globular morphologies were synthesized, blended with poly(ethylene oxide), and fabricated into composite mats via electrospinning. Notable enhancements in the mechanical properties of the composite mats were observed, attributed to the uniform distribution of the peptide assemblies within the PEO matrix and interactions between the materials. Morphological differences, such as the production of thinner nanofibers, are attributed to the increased conductivity from the zwitterionic nature of the decapeptides. Blend rheology and postprocessing analysis revealed how processing might affect the amyloid aggregation and secondary structure of the peptides. Both decapeptides demonstrated low cytotoxicity and strong antioxidant activity, indicating their potential for safe and effective use as biomaterials. This research lays the foundation for designing amyloid peptides for specific applications by defining the structure-property-processing relationships of the de novo peptide-polymer blends.