Hierarchical Structure of Polysaccharides-Peptides Hydrogels

Guy Ochbaum, Chemical Engineering, Ben Gurion University, Beer Sheva, Israel
Ronit Bitton, Chemical Engineering, Ben Gurion University, Beer Sheva, Israel

Polysaccharides such as alginate and hyaluronic acid have been utilized in the fields of regenerative medicine and tissue engineering to allow cell growth in impaired regions, by providing an artificial  bio-surrounding (scaffold) similar to the natural Extra Cellular Matrix (ECM).  A drawback of polysaccharides as a scaffold's building block is their inability to form specific cellular interactions.  On the other hand self-assembling peptides can be designed to present specific cellular interactions, however, in many cases the mechanical properties of peptide scaffolds are inadequate.  Complex hydrogel scaffolds composed of polysaccharides and self-assembling peptides have the potential for creating scaffolds (hydrogels) with superior properties.

The peptides are expected to act directly on cells, however they may also modify the hierarchical structural organization and mechanical properties of the resulting material, thus affecting the cellular response indirectly.

The aim of this research is to seek possible relationships between the Nano-structure of self-assembling peptides and the physical properties of Alginate/peptide hydrogels.

Here we present a systematic investigation of the effect of self-assembling RGD- containing peptides on the structural features and mechanical properties of the Alginate/peptide hydrogels network by using a variety of experimental techniques including Small Angle X-ray Scattering (SAXS), Rheology and electron microscopy.

Our findings show that a peptides' ability to self-assemble in aqueous solution affects the spatial organization of the alginate and the mechanical properties of the alginate/peptide hybrid hydrogel, both when the peptide is covalently attached to the alginate backbone and when peptide and alginate solutions are simply mixed together. Therefore should be taken into consideration in the design of hybrid biomaterials.