Macroporous dextran hydrogels for controlled growth factor capture and delivery using coiled-coil interactions.

Area of Science:

• Biomaterials Science
• Biomedical Engineering
• Drug Delivery Systems

Background:

• Macroporous hydrogels offer potential in biomedicine but lack controlled biomolecule capture and release due to large pores.
• Existing hydrogel systems struggle with efficient, sustained, and controlled delivery of therapeutic biomolecules.
• There is a need for biofunctionalized, affinity-based hydrogels for precise biomolecule loading and release.

Purpose of the Study:

• To develop a tunable platform for controlled capture and sustained delivery of growth factors using macroporous dextran hydrogels.
• To utilize a coiled-coil affinity pair (E/K) for biofunctionalizing hydrogels and enabling controlled biomolecule interactions.
• To investigate the impact of key parameters on growth factor loading and release kinetics.

Main Methods:

• Conjugation of Kcoil peptide to dextran backbone of macroporous hydrogels.
• Loading of Ecoil-tagged Epidermal Growth Factor (EGF) and Vascular Endothelial Growth Factor (VEGF).
• Systematic variation of macropore size, Kcoil grafting density, Ecoil valency, and E/K affinity to tune performance.

Main Results:

• Kcoil grafting increased passive growth factor capture by 20-fold compared to unmodified gels.
• Gels demonstrated sustained release, with only 20% of loaded growth factors released over one week.
• Loaded growth factors retained their bioactivity after capture and release from the hydrogel system.

Conclusions:

• A versatile and highly tunable platform for controlled growth factor delivery was successfully developed.
• The affinity-based approach enables passive loading and sustained release, suitable for in situ applications.
• These macroporous dextran hydrogels show significant promise for tissue engineering and regenerative medicine.