Polyethylene glycol-peptide hydrogels as affinity growth factor release scaffolds

Sustained delivery of growth factors is critical to support cell replacement and tissue formation at sites of injury. Hepatocyte growth factor (HGF) has been chosen in our study due to its importance in neural tissue engineering. We developed a hydrogel scaffold based on crosslinked polyethylene glycol (PEG) with incorporated affinity peptides for the purpose of controlled delivery of HGF. Whereas peptides have been routinely utilized in synthetic hydrogels to present biological cues, there has been little work to determine how covalently-bound peptides influence hydrogel physical properties. Herein we have determined that hydrogen bonding is a primary mechanism of interaction between the affinity peptide and PEG backbone. Also, profiles of HGF release from inert PEG gels and gels with affinity peptides were tested. Gels with affinity peptides had a reduced rate of HGF release, suggesting potential application for controlled delivery of HGF in vitro and in vivo.