Transforming Growth Factor β-1 Binding by Peptide Amphiphile Hydrogels

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Supramolecular Chemistry

Background:

• Supramolecular biomaterials offer versatile platforms for growth factor delivery.
• Previous work showed peptide amphiphile (PA) nanofiber hydrogels enhance cartilage regeneration.
• Deamidation of bioactive peptides complicates synthesis of well-defined structures.

Purpose of the Study:

• To synthesize novel PA molecules resistant to deamidation for improved TGFβ-1 binding.
• To investigate the impact of deamidation on chondrogenesis and growth factor retention.
• To design more effective supramolecular biomaterials for cartilage repair.

Main Methods:

• Synthesis of novel PA molecules with modified peptide sequences.
• Purification of PA nanofibers to prevent deamidation.
• Encapsulation of cells within PA hydrogels for chondrogenesis assessment.
• Quantification of growth factor retention and chondrogenic markers (Sox9, glycosaminoglycan).

Main Results:

• Novel PA nanofibers purified without deamidation were successfully synthesized.
• Deamidated PA nanofibers retained 25% more TGFβ-1 compared to native sequence nanofibers.
• Improved TGFβ-1 retention correlated with increased Sox9 expression and glycosaminoglycan production.
• Bundling of native PA nanofibers masked growth factor-binding sites.

Conclusions:

• Chemically modified PA nanofibers enhance TGFβ-1 binding and retention.
• These improved supramolecular biomaterials promote significant chondrogenesis.
• Structural changes in PA nanofibers impact biological function, enabling optimized biomaterial design.