Tuning the Supramolecular Structure and Function of Collagen Mimetic Ionic Complementary Peptides via Electrostatic...

Area of Science:

• Biomaterials Science
• Peptide Chemistry
• Tissue Engineering

Background:

• Collagen is the primary component of the extracellular matrix (ECM) and its self-assembling structure is of great interest.
• Collagen mimetic peptides are being developed to replicate complex higher-order structures and tunable mechanical properties.
• Short bioactive peptides offer a minimalistic building block for advanced biomaterials.

Purpose of the Study:

• To design and synthesize novel, oppositely charged collagen mimetic pentapeptides.
• To investigate the self-assembly and coassembly behavior of these peptides into hydrogels.
• To evaluate the potential of these coassembled hydrogels for biomedical applications, particularly in tissue engineering.

Main Methods:

• Rational design and synthesis of two pentapeptides with mutated collagen motif (Gly-X-Y) incorporating charged lysine and aspartate residues.
• Investigation of hydrogel formation at different pH conditions.
• Analysis of coassembly-induced hydrogel formation at physiological pH.
• Characterization of mechanical properties (stiffness, zeta potential) and thixotropic behavior.
• Biocompatibility assessment using fibroblast cell cytotoxicity studies.

Main Results:

• Individual peptides formed hydrogels only at acidic or basic pH, limiting applications.
• Mixing oppositely charged peptides induced coassembly, forming self-supporting hydrogels at physiological pH.
• Coassembly enhanced gel stiffness and reduced zeta potential, indicating electrostatic interactions.
• The resulting hydrogels exhibited thixotropic properties, suitable for injectable applications.
• Coassembled hydrogel nanofibers demonstrated high biocompatibility with fibroblast cells.

Conclusions:

• The rational design of oppositely charged collagen mimetic pentapeptides enables coassembly into functional biomaterials.
• Coassembly at physiological pH overcomes limitations of individual peptide hydrogels, enhancing biomedical potential.
• These designer biomaterials offer tunable mechanical properties, injectability, and excellent biocompatibility.
• This approach significantly contributes to the development of next-generation biomaterials for tissue engineering and regenerative medicine.