Controlling Affinity Binding with Peptide‐Functionalized Poly(ethylene glycol) Hydrogels

• Published in: Advanced functional materials Vol. 19; no. 14; pp. 2325 - 2331
• Main Authors: Lin, Chien‐Chi, Anseth, Kristi S.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 24.07.2009
• Subjects: biomedical materials; conjugated polymers; drug delivery; hydrogels; polymeric materials
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200900107

Poly(ethylene glycol) (PEG) hydrogels functionalized with peptide moieties have been widely used in regenerative medicine applications. While many studies have suggested the importance of affinity binding within PEG hydrogels, the relationships between the structures of the peptide motifs and their binding to protein therapeutics remain largely unexplored, especially in the recently developed thiol‐acrylate photopolymerization systems. Herein, Förster resonance energy transfer (FRET) and thiol‐acrylate photopolymerizations are employed to investigate how the architectures of affinity peptides in crosslinked hydrogels affect their binding to diffusible proteins. The binding between diffusible streptavidin and biotinylated peptide immobilized to PEG hydrogel network was used as a model system to reveal the interplay between affinity binding and peptide sequences/architectures. In addition, peptides with different structures are designed to enhance affinity binding within PEG hydrogels and to provide tunable affinity‐based controlled delivery of basic fibroblast growth factor (bFGF). This study demonstrates the importance of affinity binding in controlling the availability of hydrogel‐encapsulated proteins and provides strategies for enhancing affinity binding of protein therapeutics to bound peptide moieties in thiol‐acrylate photopolymerized PEG hydrogels. The results presented herein should be useful to the design and fabrication of hydrogels that retain and exhibit sustained release of growth factors for promoting tissue regeneration. Affinity hydrogels based on poly(ethylene glycol) (PEG) and affinity peptide are designed to enhance affinity binding within permissive hydrogel environments. This affinity hydrogel platform is useful in sustained growth factor delivery or retention of growth factor within the permissible PEG hydrogel.