Dendritic Elastin-Like Peptides as Crosslinkers in Hyaluronic Acid Gels: The Effect of Genration Number on Physical Properties

Gal Yosefi, Chemical Engineering, BGU, Beer Sheva, Israel
Yulia Shmidov, Chemical Engineering, Bgu, Beer Sheva, Israel
Mingjun Zhou, Chemistry, Virginia Tech, Blacksburg,virginia, Usa
John Matson, Virginia Tech, Blacksburg,virginia, Usa
Ronit Bitton, Chemical Engineering, Bgu, Beer Sheva, Israel

Dendrimers are uniform, highly branched macromolecules composed of repeating branching units (generations) that grow from a central core. Elastin like peptide (ELP) dendrimers are composed of a XPGXG pentapeptide repeat unit. This unique structure creates peptides that not only differ by their size and volume, but also by the number and density of their terminal functionality groups.

In our lab we have been exploring the use of thermoresponsive ELP dendrimers as building blocks for Hyaluronic Acid (HA)/ELP hydrogels. Utilizing EDC chemistry we have chemically cross linked HA to ELP dendrimers creating a swollen 3D network.    

In particular we examined the effect of ELP dendrimer generation on the HA hydrogel using Scanning electron microscopy (SEM), rheology, Small angle X-ray scattering (SAXS), swelling and release tests. Combined results from these characterization methods revealed that the peptide dendrimer generation effects the hydrogels stiffness, swelling ability, turbidity and nanostructure.

Understanding the connections between the peptide dendrimer generation and changes in these hydrogels structure-physical properties will allow us to produce a new thermoresponsive material with tailored properties which can be used for biomedical applications (e.g. drug delivery, tissue engineering etc.)