Improvement of self-assembling peptide scaffold biomechanical properties

Abstract

Tissue engineering aims at regenerating damaged tissues/organs via scaffolds that mimic extra cellular matrix (ECM), which is the native cellular environment. In this regard, self-assembled nanostructures based on peptides (SAPs) offer several advantages: 1) SAPs are easily synthetized starting from amino acidic precursors; 2) they are designed to self-assemble into structures at the nano-scale; 3) external stimuli, such as pH, salt concentration or temperature shifts, trigger their assembling; 4) SAPs can be functionalized with biologically active motifs. However, despite SAP scaffolds fairly resembling native cellular environment, they lacks in some ECM features, i.e. high elasticity, stiffness or resistance to mechanical stress. This work shows a new method to improve biomechanics of SAPs by use of Genipin (G) a non-toxic agent, that can cross-link the amine groups found in biological tissues and polymers. Particularly, this dissertation explores the use of G on functionalized SAPs designed to mimic the ECM and to potentially support nervous regeneration. Chemical physical characterization suggests that G effectively cross-links different functionalized SAPs stabilizing their nanofiber bonds. Moreover, these materials show values of stiffness far superior to standard SAPs used until now. This strategy will lead to optimized biological performance of SAPs and potentially open their field of application to the regeneration of various tissues like bone, cartilage and skin.