Materials & Design (Sep 2020)

Superior mechanical and optical properties of a heterogeneous library of cross-linked biomimetic self-assembling peptides

  • Raffaele Pugliese,
  • Luca Moretti,
  • Margherita Maiuri,
  • Tiziana Romanazzi,
  • Giulio Cerullo,
  • Fabrizio Gelain

Journal volume & issue
Vol. 194
p. 108901

Abstract

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Self-assembling peptides (SAP) are ideal components for biomedical devices. However, their practical applications have been limited due to their intrinsic unstable, low-performance, and low-stress response given by non-covalent interactions involved in self-assembling. Herein, a library of SAPs featuring different self-assembled nanostructures was successfully cross-linked with genipin, allowing to produce nanofibrous hydrogels with enhanced mechanical properties (G′ ≥ 0.2 MPa, stress-failure ≥ 3.5 kPa) and enhanced thermostability (≥100 °C) while maintaining their native nanoarchitecture. Cross-linking dramatically changed the optical properties of SAPs: it triggered new absorption/fluorescence bands in the visible spectral range, which are attributed to charge transfer between peptide chains. Genipin cross-linking, fitted for different classes of SAPs, could be a powerful tool to obtain biomimetic SAP scaffolds with tunable stiffness and thermostability. Lastly, because of the changed absorption/emission properties and relaxation kinetics of cross-linked SAPs, genipin cross-linking may bestow novel optical properties to several well-known lysine-containing SAPs, with intriguing potential for biomedical imaging, photonics and optoelectronics.

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